System Design Guide for Software Professionals E-Book

Dhirendra Sinha

• Herausgeber: Packt Publishing
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 507

Veröffentlichungsjahr: 2024

Beschreibung

Building scalable software systems is more critical than ever. Yet, many software professionals struggle to navigate the complexities of system design, especially when aiming for positions at top tech companies. Written by Dhirendra Sinha, a seasoned Engineering Leader at Google with a blend of experience working at large companies such as Cisco, Oracle, and Yahoo, and Tejas Chopra, a Senior Software Engineer at Netflix, a TEDx speaker, and a Co-Founder of GoEB1, this comprehensive and authoritative resource on system design offers invaluable insights and strategies to help you excel in interviews with all major tech companies.
This guide covers the basics of system design, including the principles and techniques of distributed systems, and delves into core building blocks such as distributed system theorems, attributes, and the design and implementation of system components. Following examples of popular applications such as Uber, Twitter, Instagram, Google Docs, and Netflix, you’ll learn how to apply concepts to real-world scenarios. The book offers expert advice and strategies for preparing and acing system design interviews, along with a mind map/cheat sheet summarizing the key takeaways.
By the end of this book, you’ll be equipped with unique techniques and the confidence to solve any coding interview question.

Leseprobe

System Design Guide for Software Professionals

Build scalable solutions – from fundamental concepts to cracking top tech company interviews

Dhirendra Sinha

Tejas Chopra

System Design Guide for Software Professionals

Copyright © 2024 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the authors, nor Packt Publishing or its dealers and distributors, will be held liable for any damages caused or alleged to have been caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

Associate Group Product Manager: Kunal Sawant

Publishing Product Manager: Akash Sharma

Book Project Manager: Deeksha Thakkar

Senior Editor: Esha Banerjee

Technical Editor: Vidhisha Patidar

Copy Editor: Safis Editing

Proofreader: Esha Banerjee

Indexer: Hemangini Bari

Production Designers: Joshua Misquitta and Ponraj Dhandapani

DevRel Marketing Coordinator: Sonia Chauhan

First published: August 2024

Production reference: 1300724

Published by Packt Publishing Ltd.Grosvenor House
11 St Paul’s SquareBirmingham
B3 1RB, UK

ISBN 978-1-80512-499-3

www.packtpub.com

To my parents, whose unwavering support and love have been my greatest source of strength. Your belief in me has always been the foundation upon which I've built my dreams.

To my lovely wife, Shruti, for her endless patience, understanding, and constant encouragement. Your love has been my guiding light, and your unwavering support has given me the strength to persevere.

To my kids Kunshi and Kavni, for their boundless energy and joy, which have been a constant source of inspiration. Your curiosity and enthusiasm for learning inspire me every day.

To my teachers, who imparted wisdom and inspired a lifelong love of learning. Your dedication and passion for teaching have left an indelible mark on my life and career.

To all the book authors, blog writers, and content creators who have expressed their thoughts and shared their expertise in the area of software system design. Your insights and contributions have been invaluable, and this book is a testament to the collective knowledge and creativity of our community.

Dhirendra Sinha

To Mahima, my loving wife and steadfast partner in this journey – your unwavering support and encouragement have been my anchor. And to our little wonder, Nyra – your curiosity lights up my world and fuels my passion to explain even the most complex ideas.

To my parents and sister, Anchal – your love, guidance, and belief in me have shaped not just this book, but the person I am. Your support has been the wind beneath my wings, pushing me to explore new heights in technology and life.

This book is a labor of love, inspired by and dedicated to all of you. Thank you for being my strength, my motivation, and my joy.

Tejas Chopra

Contributors

About the authors

Dhirendra Sinha is a Software Engineering Manager at Google. He is an angel investor and has served as a Strategic and Technology advisor at a few startups. Dhirendra has around two decades of experience in the Software Engineering field building highly scalable complex distributed systems and managing multiple Engineering teams. While he has experience in working at large companies such as Cisco, Oracle, Yahoo, and Google, he has also been involved with early and late stage startups in leadership positions. In addition to his strong Software Engineering experience, he has been teaching the Distributed System Design course for the last seven years. He has also been coaching and mentoring Software Engineers and Software Engineering Managers for over a decade. He completed his Bachelor of Technology degree from IIT Guwahati and Master of Science from Texas A and M University, College Station, Texas.

Tejas Chopra is a Senior Engineer at Netflix working on building the Machine Learning Platform powering Netflix recommendations and personalization. He is also a Co-founder at GoEB1, which is the world’s first thought leadership platform for immigrants. Tejas is a recipient of the prestigious EB1A (Einstein) visa in the US. He is a Tech 40 under 40 Award winner, a 2xTEDx speaker, a British Computer Society (BCS) Fellow, and has spoken at conferences and panels on Cloud Computing, Blockchain, Machine Learning, Software Development, and Engineering Leadership. Tejas has been awarded the “International Achievers Award, 2023” by the Indian Achievers’ Forum.
He is an Adjunct Professor of Software Development at the University of Advancing Technology, Arizona, an Angel Investor, and has previously been an Advisor to startups such as Nillion, Inc.
He is also a member of the Advisory Board for Future of Memory and Storage Summit. Tejas’ experience has been in companies such as Box, Apple, Samsung, Cadence, and Datrium. Tejas holds a Masters Degree in Electrical & Computer Engineering from Carnegie Mellon University, Pittsburgh.

About the reviewers

Ruchi Agarwal is a Senior Software Engineer currently working as a technical lead at Netflix, with over 13 years of experience in building and leading technical projects across multiple high-tech companies, including Netflix, Apple, and eBay

At Netflix, Ruchi was the first hired engineer in the internal employees’ applications team that builds solutions for company-wide usages. Building the team from its inception, she played a critical role in setting the engineering direction and building essential tools to streamline Netflix's corporate operations for its employees.

As a technical leader, Ruchi has spearheaded numerous projects integral to the operations of Netflix, which employs over 12,000 people. Ruchi led and architected numerous projects at Netflix that saved the company millions of dollars in annual revenue.

During her time at Apple, Ruchi was a critical resource in building tools that played a crucial role in the development of new iPhones.

Ruchi actively champions the empowerment of women in the tech industry and inspires students through impactful speaking engagements ensuring that the voices and perspectives of women continue to shape the future of technology

Chinmay Abhay Nerurkar is a highly respected Engineering Leader with 15+ years of diverse industry experience in building enterprise-scale software products using AI/ML, Big Data, Distributed System Design, and Cloud technologies. He is currently a Principal Engineer at Microsoft AI, leading strategic engineering initiatives on the Microsoft Copilot Platform.

Chinmay is an experienced career mentor who coaches engineering managers and individual contributors on all-rounded growth. His passion lies in cultivating an inclusive, empowering team culture while promoting engagement and driving innovation. Chinmay is also a sought-after keynote speaker who has presented at major international conferences such as P99 CONF, DeveloperWeek NYC, AI DevWorld SFO, Graph+AI ML, etc. and has chaired multiple industry advisory boards. He is a Fellow at the Institution of Engineering and Technology and at the British Computing Society, Senior Member at IEEE, and Senior Fellow at AI 2030 think-tank for Responsible AI.

Table of Contents

Preface

Part 1: Foundations of System Design

1

Basics of System Design

What is system design?

Software system

Distributed software system

Understanding system design

What are the types of system design?

High-level system design

System architecture

Data flow

Scalability

Fault tolerance

Low-level system design

Algorithms

Data structures

APIs

Code optimization

Importance of system design in the industry

Practical examples of the importance of system design

Summary

2

Distributed System Attributes

A hotel room booking example

Consistency

Strong consistency

Eventual consistency

Availability

Understanding partition tolerance

Network partition

Partition tolerance

Latency

Durability

Reliability

Fault tolerance

Scalability

Vertical scaling

Horizontal scaling

Summary

3

Distributed Systems Theorems and Data Structures

CAP theorem

PACELC theorem

Paxos

Raft

BGP

The Byzantine fault

Byzantine fault tolerance

Modern BFT

FLP impossibility theorem

Consistent hashing

Bloom filters

Count-min sketch

HyperLogLog

Summary

Part 2: Core Components of Distributed Systems

4

Distributed Systems Building Blocks: DNS, Load Balancers, and Application Gateways

Exploring DNS

DNS querying

Scalability, reliability, and consistency in DNS

Scalability

Reliability

Consistency

Load balancers

Placing load balancers

Advantages of load balancers

Global and local load balancing

DNS and GSLB

Load balancer algorithms

Load balancing at different layers of the Open Systems Interconnection (OSI) model

Deployment of load balancers

Implementing load balancers

Application gateways

Features and capabilities

Microservices architectures

Cloud-native implementations

On-premises options

Summary

5

Design and Implementation of System Components –Databases and Storage

Databases

Types of databases

Relational databases

NoSQL databases

The advantages and disadvantages of relational and NoSQL databases

NoSQL databases

Key-value stores

What is a key-value store?

Use in distributed systems

Designing a key-value store

Enhancing scalability and data replication

Boosting scalability

Consistent hashing

Virtual nodes

Data duplication strategies

Implementing get and put functions

Implementing get and put operations

Using r and w

Ensuring fault tolerance and identifying failures in a key-value store

Managing temporary failures

Addressing permanent failures

Ring membership promotion for failure detection

A system design interview – key value store design questions and strategies

DynamoDB

No fixed schema

API functions

Partitioning data in DynamoDB

Throughput optimizations in DynamoDB

High availability in DynamoDB

Column-family databases

HBase

HBase details

Graph-based databases

The Neo4j graph database

Neo4j details

Relational modeling versus graph modeling

Graph modeling

Adding a new node to an existing graph

Summary

References

6

Distributed Cache

What is caching?

What is distributed caching?

How is it different from regular caching?

Use cases

Benefits of using a distributed cache

Challenges of using distributed caching

Designing a distributed cache

Requirements

Design journey

Popular distributed cache solutions

Redis

Memcached

How to choose between Redis and Memcached

Summary

7

Pub/Sub and Distributed Queues

The evolution of distributed systems

Designing a distributed queue

Designing a pub/sub system

Key characteristics of pub/sub systems

Pub/sub system design considerations

Kafka

The importance of Kafka in distributed systems

Kafka Streams

Kinesis

Summary

Part 3: System Design in Practice

8

Design and Implementation of System Components: API, Security, and Metrics

REST APIs

Design principles of REST APIs

Use cases for REST APIs

Strengths and weaknesses

gRPC APIs

Design principles of gRPC APIs

Use cases for gRPC APIs

Strengths and weaknesses

Comparing REST and gRPC

API security

Authentication

Authorization

Secure communication of APIs

Rate limiting

Distributed systems logging

Centralized logging

Best practices for implementing distributed logging

Metrics in a distributed system

Types of metrics

Open source tools for metrics

Best practices for implementing metrics

Alerting in a distributed system

Designing effective alerts

Open-source tools for alerting

Best practices for implementing alerting

Tracing in a distributed system

Distributed tracing

Open-source tools for distributed tracing

Best practices for implementing tracing

Best practices

Summary

9

System Design – URL Shortener

Real-world use cases

Functional requirements

Non-functional requirements

Client APIs needed

Estimates and calculations

System design

Core challenge

Choice of database

High-level solution architecture

Requirements verification

Summary

10

System Design – Proximity Service

Real-world use cases

Functional requirements

Non-functional requirements

Client APIs needed

Estimates and calculations

System design

High-level system design

Core challenge

Final high-level solution architecture

Requirements verification

Summary

11

Designing a Service Like Twitter

Functional requirements

Non-functional requirements

Data model

Scale calculations

Exploring high-level design

Microservices architecture

Designing Tweet Service

Data storage

Tweet creation flow

Tweet retrieval flow

Caching

Designing User Service

Data storage

User registration flow

User authentication flow

Follow/unfollow flow

Retrieving followers/followees

Low-level design – Timeline Service

Data flow

Timeline retrieval flow

Push-based updates

Designing Search Service

Data flow and indexing

Search query processing

Relevance scoring and ranking

Additional considerations

Summary

12

Designing a Service Like Instagram

Functional requirements

Non-functional requirements

Designing the data model

Scale calculations

High-level design

Components and modules in the high-level architecture

Low-level design

Designing the Photo Upload Service

News Feed Service

User Service

Additional considerations

Summary

13

Designing a Service Like Google Docs

Functional requirements

Non-functional requirements

Data model

Relationships

Scale calculations

Assumptions

Storage requirements

Bandwidth considerations

Processing requirements

High-level design

Software components and modules of high-level design

Low-level design

Designing the document service

Designing the Collaboration Service

Designing the Access Control Service

Additional considerations and best practices

Summary

14

Designing a Service Like Netflix

Functional requirements

Non-functional requirements

Designing the data model

Relationships

Scale calculations

Assumptions

Storage estimation

Bandwidth estimation

Processing estimation

High-level design

Low-level system design

Video Service

Video upload and storage

Video encoding and transcoding

Video streaming

Caching and content delivery

User Service

User authentication and authorization

User profile management

Database and caching

Recommendation Service

The CDN

CDN architecture and content distribution

Request routing and video streaming

Adaptive bitrate streaming

Content security and DRM

Summary

15

Tips for Interviewees

Tips for preparation for system design interviews

Understanding the fundamentals

Studying common system design patterns

Practicing designing systems

Learning from online resources

Honing your communication skills

Reviewing and reflecting

Tips for the interview session

Understanding the problem statement

Breaking down the problem

Key steps to follow

Communicating your solution effectively

Summary

16

System Design Cheat Sheet

Which data store should we use for a use case?

Which data structures should we use for a use case?

Which components should we use for which use case?

What protocol should we use for which use case?

Which solution should we use for which core challenge?

Summary

Index

Preface

Hello there! System Design is a crucial skill in the world of software engineering and architecture. It involves the process of defining the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. This book aims to provide a comprehensive guide to system design, covering both theoretical concepts and practical applications through real-world examples.

The field of system design is vast and ever-evolving, with new technologies and paradigms emerging constantly. As software systems become increasingly complex and distributed, the ability to design scalable, reliable, and efficient systems has become extremely important. This book strives to equip you with the necessary knowledge and tools to tackle complex system design challenges in today’s technology landscape.

There are three main aspects that this book focuses on:

Fundamental concepts and principles of system designKey components and technologies used in modern distributed systemsReal-world system design case studies and their analysis

We will cover these aspects in-depth, providing you with a solid foundation in system design theory while also offering practical insights drawn from industry experience and best practices.

Throughout this book, we will provide relevant information and guide you through various system design concepts, techniques, and case studies. The content is based on two main sources of information:

Our experience and knowledge from years of working in the software industry and designing large-scale systemsInterviews and insights from industry experts and system design practitioners across different domains and companies

As per recent industry reports, the demand for professionals skilled in system design has been growing rapidly. Companies of all sizes, from startups to tech giants, are constantly seeking engineers who can architect and design scalable, robust systems. This trend is expected to continue in the coming years, as businesses increasingly rely on complex software systems to drive their operations and innovations.

One of the major challenges faced by many aspiring system designers is bridging the gap between theoretical knowledge and practical application. This book aims to address this challenge by not only explaining the core concepts but also demonstrating how these concepts are applied in real-world scenarios. By the end of this book, you should be well-equipped to tackle system design interviews and real-world design problems with confidence.

Who this book is for

This book is designed for a wide range of readers in the software engineering field. The three main personas who are the target audience of this content are as follows:

Software engineers and developers: Those looking to expand their skills beyond coding and keen on understanding how large-scale systems are designed and architected. This book will help them grow in their career toward becoming senior engineers, tech leads, and system architects.System design interview candidates: Professionals preparing for system design interviews at top tech companies. The book covers common interview topics and provides a structured approach to solving design problems.Engineering managers and tech leads: Those who want to gain a deeper understanding of system design principles to better guide their teams and make informed architectural decisions.Computer science students: Advanced students who want to supplement their theoretical knowledge with practical insights into how real-world systems are built.

What this book covers

Chapter 1, Basics of System Design, provides an introduction to the field of system design. It explains the different types of system designs and emphasizes the importance of system design in the industry. This chapter sets the foundation for the rest of the book.

Chapter 2, Distributed System Attributes, delves into the fundamental concepts that underpin modern system design. It covers crucial topics such as consistency, availability, partition tolerance, latency, durability, reliability, and fault tolerance. Understanding these principles is essential for designing robust and scalable systems.

Chapter 3, Distributed Systems Theorems and Data Structures, explores the theoretical underpinnings of distributed systems. It covers important theorems and algorithms such as the CAP theorem, PACELC theorem, Paxos and Raft algorithms, and the Byzantine Generals Problem. It also introduces key concepts such as consistent hashing, Bloom filters, and HyperLogLog, which are frequently used in large-scale system design.

Chapter 4, Distributed Systems Building Blocks: DNS, Load Balancers, and Application Gateways, focuses on the core components of networked systems. It provides an in-depth look at DNS, load balancers, and application gateways, which are crucial for building scalable and reliable distributed systems.

Chapter 5, Design and Implementation of System Components — Databases and Storage, is dedicated to the various types of databases used in modern system design. It covers relational and NoSQL databases and dives into specific technologies such as Cassandra, HBase, DynamoDB, and S3. It also includes a section on designing a key-value store and an overview of Lucene search.

Chapter 6, Distributed Cache, explores the world of distributed caching. It covers the design of distributed cache systems and provides detailed information on popular caching solutions such as Redis and Memcached.

Chapter 7, Pub/Sub and Distributed Queues, focuses on designing distributed queues and publish-subscribe systems. It provides an in-depth look at technologies such as Kafka and Kinesis, which are crucial for building real-time data processing systems.

Chapter 8, Design and Implementation of System Components: API, Security, Metrics, covers the essential aspects of designing and maintaining APIs in distributed systems. It explores REST and gRPC protocols, API security basics, and the crucial components of system observability: logging, metrics, alerting, and tracing.

Chapters 9 to 16 are dedicated to real-world system design case studies. Each of these chapters follows a consistent structure:

Requirements of the systemHigh-level designDetailed designEvaluation of the design

These case studies cover a wide range of popular systems:

Chapter 9: System Design – URL ShortenerChapter 10: System Design – Proximity ServiceChapter 11: Designing a Service Like TwitterChapter 12: Designing a Service Like InstagramChapter 13: Designing a Service Like Google DocsChapter 14: Designing a Service Like NetflixChapter 15: Tips for InterviewsChapter 16: System Design Cheat Sheet

Note

By working through these case studies, readers will gain practical experience in applying system design principles to real-world scenarios. These chapters will help bridge the gap between theory and practice, providing invaluable insights into how large-scale systems are designed and implemented in industry.

The book concludes with guidance on approaching system design interviews. This section covers the format of system design interviews, what interviewers are looking for, and the importance of this type of interview in the hiring process. It also provides tips on asking relevant questions, considering boundary conditions, making back-of-the-envelope calculations and estimations, and designing systems based on access patterns.

To get the most out of this book

To fully benefit from this book, readers should have a basic understanding of computer science concepts, data structures, and algorithms. Familiarity with at least one programming language and basic networking concepts will also be helpful. However, we’ve strived to make the content accessible to readers from various backgrounds by explaining concepts clearly and providing the necessary context.

We recommend reading this book sequentially, as the later chapters build upon concepts introduced in the earlier ones. However, experienced readers may choose to jump directly to specific topics or case studies of interest. As you progress through the book, we encourage you to actively engage with the material. Try to solve the design problems presented in the case studies before reading the proposed solutions. This approach will help you develop your own system design thinking and problem-solving skills.

Remember that system design is as much an art as it is a science. While this book provides a solid foundation and numerous examples, there’s often no single “correct” solution to a design problem. The best designs often emerge from balancing various trade-offs and considering the specific context and requirements of each situation.

We’ve also included numerous diagrams and illustrations throughout the book to help visualize complex concepts and system architectures. These visual aids are crucial in system design, both for understanding and communicating ideas effectively.

Finally, system design is a field that’s constantly evolving. While this book covers the fundamental principles and current best practices, we encourage you to stay curious and continue learning beyond this book. Keep up with industry trends, new technologies, and case studies of how leading companies are solving their scaling challenges.

We hope this book serves as a valuable resource in your journey to mastering system design. Whether you’re preparing for interviews, looking to advance in your career, or you are simply passionate about building large-scale systems, we believe you’ll find the content both informative and practical.

Thank you for choosing this book. We’re excited to embark on this learning journey with you. Let’s dive in and explore the fascinating world of system design together!

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “The Comment entity represents the comments posted on photos. It contains the comment text, user_id of the commenter, photo_id of the associated photo, and creation timestamp.”

A block of code is set as follows:

Request: {   "userId": "12345",   "restaurantId": "78566",   "items": [     {       "itemId": "item1",       "quantity": 4     },     {       "itemId": "item2",       "quantity": 3     }   ],   "paymentMethod": "credit_card" }

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “ The Photo Upload Service will expose the following API endpoints.”

Tips or important notes

Appear like this.

Get in touch

Feedback from our readers is always welcome.

General feedback: If you have questions about any aspect of this book, email us at [email protected] and mention the book title in the subject of your message.

Errata: Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you have found a mistake in this book, we would be grateful if you would report this to us. Please visit www.packtpub.com/support/errata and fill in the form.

Piracy: If you come across any illegal copies of our works in any form on the internet, we would be grateful if you would provide us with the location address or website name. Please contact us at [email protected] with a link to the material.

If you are interested in becoming an author: If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, please visit authors.packtpub.com.

Share Your Thoughts

Once you’ve read System Design Guide for Software Professionals, we’d love to hear your thoughts! Please click here to go straight to the Amazon review page for this book and share your feedback.

Your review is important to us and the tech community and will help us make sure we’re delivering excellent quality content.

Download a free PDF copy of this book

Thanks for purchasing this book!

Do you like to read on the go but are unable to carry your print books everywhere?

Is your eBook purchase not compatible with the device of your choice?

Don’t worry, now with every Packt book you get a DRM-free PDF version of that book at no cost.

Read anywhere, any place, on any device. Search, copy, and paste code from your favorite technical books directly into your application.

The perks don’t stop there, you can get exclusive access to discounts, newsletters, and great free content in your inbox daily

Follow these simple steps to get the benefits:

Scan the QR code or visit the link below

https://packt.link/free-ebook/9781805124993

Submit your proof of purchaseThat’s it! We’ll send your free PDF and other benefits to your email directly

Part 1: Foundations of System Design

In this Part, you will gain a comprehensive understanding of the fundamental concepts and principles that underpin modern system design. We’ll start by exploring the essence of system design, its various types, and its critical importance in today’s technology-driven industry.

As we delve deeper, you’ll learn about the key principles of distributed systems, which form the backbone of most large-scale applications today. We will cover crucial concepts such as consistency, availability, partition tolerance, latency, durability, reliability, and fault tolerance.

We’ll then explore the theoretical foundations that guide system design decisions. You will learn about important theorems and algorithms such as the CAP theorem, PACELC theorem, Paxos and Raft algorithms, and the Byzantine Generals Problem. We’ll also introduce you to practical concepts such as consistent hashing, Bloom filters, and HyperLogLog, which are frequently used in large-scale system design.

By the end of this section, you'll have a solid theoretical foundation that will inform your approach to designing and architecting large-scale systems.

This Part has the following chapters.

Chapter 1, Basics of System DesignChapter 2, Distributed System AttributesChapter 3, Distributed Systems Theorems and Data Structures

1

Basics of System Design

System design is an essential process in software engineering that involves designing a software system’s architecture, components, interfaces, and data management strategies. A well-designed system can improve the system’s overall performance, user experience, and security while reducing development costs and time.

This chapter introduces the topic of software system design and talks about the various types and the significance of system design in the software industry. The chapter also discusses system design’s impact on software development, maintenance, and overall system performance. By the end of this chapter, you will have a good background in software system design and its importance in software development and have the motivation to dive into this topic even further.

In this chapter, we will cover the following:

What is system design?What are the different types of system design?Importance of system design in the industry

What is system design?

Software system design is the process of defining the architecture, components, interfaces, and other characteristics of a system to satisfy specified requirements.

Let’s gain an understanding of system design by first delving into the concepts of software systems and distributed software systems.

Software system

A software system is a collection of software components, modules, and programs that work together to perform a specific task or set of tasks. It typically includes a set of interrelated software applications that work together to provide a desired functionality, such as managing data, processing transactions, or delivering a service to end users.

It can be as simple as a single program or as complex as a distributed system that spans multiple computing devices and networks.

A software system is designed, developed, and maintained by software engineers, who use various tools, programming languages, and methodologies to ensure that the system is reliable, scalable, and secure. The software system may also require regular updates and maintenance to keep it functioning properly and to address any issues or bugs that arise over time.

Distributed software system

A distributed software system consists of multiple independent components, processes, or nodes that communicate and coordinate with each other to achieve a common goal. Unlike a centralized software system, where all the components are located on a single machine, a distributed software system is spread across multiple machines, networks, and geographical locations (see Figure 1.1).

Each component in a distributed software system is responsible for a specific task or set of tasks, and they work together to achieve a common goal. The components communicate with each other using a variety of communication protocols, such as remote procedure calls (RPCs), message passing, or publish-subscribe mechanisms.

Distributed software systems are often used in large-scale applications where scalability, availability, and fault tolerance are critical requirements. Examples of distributed software systems include cloud computing platforms, peer-to-peer networks, distributed databases, and content delivery networks (CDNs).

Designing, developing, and maintaining a distributed software system can be challenging because it requires careful consideration of network communication, data consistency, availability, fault tolerance, and security.

Figure 1.1 – An example of a distributed system

Figure 1.1 shows an example of a distributed system with multiple computer resources and networks. There are user devices (laptops, mobile phones, and tablets) on the left side, which the user interfaces with to submit requests and consume information. These requests then are routed to servers via the DNS server and load balancer to be processed. The server talks to different types of storage systems and databases to fetch the data needed to process and respond to the original request.

Understanding system design

System design is the process of defining the architecture, components, modules, interfaces, and interactions of a software system to meet its functional and non-functional requirements. It involves transforming a set of requirements into a blueprint or a plan that describes how the software system will be structured, implemented, and maintained.

Note

The goal of software system design is to create a design that is easy to understand, maintain, and extend and that meets the performance, scalability, reliability, and security requirements of the system. The design should also be flexible enough to accommodate changes in the requirements or the environment over time.

The software system design process typically involves the following steps:

Requirements analysis: Understanding and defining the functional and non-functional requirements of the system. This step also calls for a deeper look into the read-and-write patterns and then designing the system to take advantage of these patterns.High-level architecture design: Defining the overall structure of the system (see Figure 1.2), including its components, modules, and interfaces.Detailed design: Defining the internal structure and behavior of each component and module. This also involves the core algorithms of each component and mechanisms of interactions between components.User interface design: Designing the user interface of the system that would interact with the backend services via APIs. This is to be done at a very high level.API design: Defining proper APIs, which would enable the user interface or the frontend to interact with the backend services.Database design: Designing the data structures and storage mechanisms used by the system. The database could be simple file storage to a relational database such as MySQL or a NoSQL database such as HBase or Cassandra.

Figure 1.2 – A simple high-level system design diagram of a typical web application

Here, in Figure 1.2, we can see an example of a high-level system design architectural diagram, which you can refine as you move on to a more detailed design by adding more components and systems.

The output of the software system design process is a set of design documents, such as architectural diagrams and detailed design documents, enlisting and defining the APIs and user interface prototypes, which serve as a blueprint for implementing the software system.

What are the types of system design?

There are essentially two types of system design: architectural design, also referred to as high-level system design, and detailed design, also referred to as low-level system design.

High-level system design

The key aspects of high-level system design include the following:

System architecture: The overall structure of the system, including its components, relationships, and communication patternsData flow: The movement of data through the system, from ingestion to storage and processingScalability: The ability of the system to handle increased workloads without significant degradation in performanceFault tolerance: The capacity of the system to continue functioning despite failures or errors

Let us look at each of these aspects in some more detail.

System architecture

A crucial aspect of high-level system design is defining the overall architecture, which outlines the main components, their relationships, and communication patterns. Some popular architectural patterns include the following:

Monolithic: A single, self-contained application that combines all system componentsClient-server: A distributed architecture where clients request services from one or more serversMicroservices: A modular architecture with small, independent services that communicate over a networkEvent-driven: A system where components communicate through asynchronous events or messages

When designing a system architecture, consider the following factors:

Scalability: Will the architecture support the system’s growth in terms of users, data, and functionality?Maintainability: How easy will it be to update, debug, or enhance the system?Reliability: Can the architecture ensure the system’s uptime, fault tolerance, and resilience?Latency: How will the architecture affect the system’s response time and performance?

High-level system design focuses on the clarity of system architectural choices. Let us now look into the next aspect, the flow of the data in the system.

Data flow

Understanding how data flows through the system is another essential aspect of high-level system design. A well-designed data flow ensures that the system can ingest, process, store, and retrieve data efficiently. When designing the data flow, consider the following:

Data ingestion: Identify the sources of data and the mechanisms for ingesting it into the system (e.g., APIs, streaming, or batch processing).Data storage: Determine the appropriate storage solutions for the data, considering factors such as access patterns, query performance, and consistency requirements.Data processing: Design the processes that transform, analyze, or aggregate the data, considering the necessary compute resources and potential bottlenecks.Data retrieval: Define how the processed data is accessed by clients or other components, considering latency, caching, and load balancing strategies.

Data flow directly impacts system performance, scale, and usability. Hence, it is important to make the right choices in selecting and/or designing the data flow subsystems.

Scalability

Scalability is a critical aspect of high-level system design, as it determines the system’s ability to handle increased workloads without significant degradation in performance. There are two primary types of scalability:

Vertical scalability: Improving performance by adding resources to a single component, such as increasing CPU, memory, or storageHorizontal scalability: Improving performance by distributing the workload across multiple components or instances, such as adding more servers to a cluster

When designing for scalability, we must consider load balancing, caching, data partitioning, and exploring stateless services. Let us look at the final aspect of high-level system design, that is, fault tolerance.

Fault tolerance

Fault tolerance is the system’s ability to continue functioning despite failures or errors in its components. A fault-tolerant system is more reliable and less prone to downtime. Some key strategies for designing fault-tolerant systems include replication, redundancy, graceful degradation, monitoring, and self-healing.

In short, high-level system design focuses on the high-level architecture of the system and does not delve into the implementation and optimizations. Let us now explore low-level system design.

Low-level system design

Low-level system design focuses on the implementation details of the system’s components. This includes selecting appropriate algorithms, data structures, and APIs to optimize performance, memory usage, and code maintainability.

Key aspects of low-level system design include the following:

Algorithms: The step-by-step procedures for performing calculations, data processing, and problem-solvingData structures: The organization and management of data in memoryAPIs: The interfaces that enable communication between different components or servicesCode optimization: Techniques to improve code performance, readability, and maintainability

Let us now look into each of these aspects in some more detail.

Algorithms

Algorithms are step-by-step procedures for performing calculations, data processing, and problem-solving in low-level system design. Choosing efficient algorithms is essential to optimize the system’s performance, resource usage, and maintainability. When selecting an algorithm, consider the following factors:

Time complexity: The relationship between the input size and the number of operations the algorithm performsSpace complexity: The relationship between the input size and the amount of memory the algorithm consumesTrade-offs: The balance between time and space complexity, depending on the system’s requirements and constraints

Writing an optimized algorithm is a far better choice than leveraging high-end machines in any system. Hence, it is one of the core pillars of a robust system. Algorithms can be optimized by the use of appropriate data structures, which we will cover next.

Data structures

Data structures are used to organize and manage data in memory, impacting the system’s performance and resource usage. Choosing appropriate data structures is crucial for low-level system design. When selecting a data structure, consider the following factors:

Access patterns: The frequency and nature of data access, including reads, writes, and updatesQuery performance: The time complexity of operations such as search, insertion, and deletionMemory usage: The amount of memory required to store the data structure and its contents

Some common data structures used in system design include arrays, linked lists, hash tables, trees, and graphs.

APIs

Application programming interfaces (APIs) are essential for communication between different components or services in a system. They define the contracts that enable components to interact while maintaining modularity and separation of concerns. When designing APIs, consider thefollowing factors:

Consistency: Ensure that the API design is consistent across all components, making it easy to understand and useFlexibility: Design the API to support future changes and extensions without breaking existing functionalitySecurity: Implement authentication, authorization, and input validation to protect the system from unauthorized access and data breachesPerformance: Optimize the API for low latency and efficient resource usage

Having clean and clear APIs is often an enabler to building backward-compatible systems.

Code optimization

Code optimization refers to techniques that improve code performance, readability, and maintainability. In low-level system design, code optimization is essential for ensuring that the system performs well under real-world conditions. Some code optimization techniques include the following:

Refactoring: Restructure the code to improve its readability and maintainability without changing its functionalityLoop unrolling: Replace repetitive loop structures with a series of statements, reducing loop overhead and improving performanceMemorization: Reduce time to recompute results by storing the results of previous callsParallelism: Break down tasks into smaller, independent subtasks that can be executed concurrently, reducing overallprocessing time

We have just provided a flavor of some of the techniques to optimize code. This is a broad topic and has several books and other resources dedicated to it. We would highly recommend you carry out some online research on this topic. Thus, low-level system design focuses on the implementation, interface, and optimization of the system.

We have provided a very high-level overview here of the types of system design. Depending on the stage of the project, you may, as an architect, find yourself dabbling in different forms of system design aspects.

Importance of system design in the industry

Incorporating the right process for system design has several benefits. Some of them are as follows:

Clarity of understanding the requirements: System design enables a clear understanding of requirements, which helps in building the right solution for the problem. This includes identifying the core functionalities, performance, and security requirements of the system.Better collaboration: System design helps teams to collaborate more effectively, ensuring that everyone involved in the project has a clear understanding of the system’s architecture and design. This leads to better communication and coordination among team members and stakeholders.Design reviews and feedback: Having a system design in place makes it easier for teammates and architects to participate in design reviews to discuss, find issues, and incorporate feedback.High scalability: Scalability is the ability of a system to handle increasing amounts of data or traffic without compromising performance. System design helps to identify the scalability requirements of the system and design it in a way that can be easily scaled up or down as needed.Performance: System design ensures that the software solution performs optimally under different loads and usage patterns and avoids performance bottlenecks by thinking ahead of time. It also takes into account factors such as response time, reliability, and availability, which are critical for ensuring user satisfaction.Maintainability: A well-designed system is easier to maintain and update, reducing the cost of maintenance and improving the system’s longevity.Cost-effectiveness: A well-designed system can be built more efficiently and cost-effectively, as it reduces the risk of errors and rework.

Overall, system design plays a critical role in the development of efficient, effective, and scalable systems that meet the needs of end users and stakeholders.

Practical examples of the importance of system design

The following are practical examples of the importance of software system design in various industries:

Finance: Financial institutions rely heavily on software systems to manage transactions, customer accounts, and other critical operations. Software system design ensures that these systems are secure, reliable, and efficient.E-commerce: E-commerce platforms require complex software systems to handle large volumes of online transactions and manage inventory, shipping, and customer information. Effective software system design ensures that these platforms are user-friendly, secure, and scalable.Healthcare: Electronic health records, medical imaging systems, and other healthcare software applications are critical to patient care. Software system design ensures that these applications are reliable, secure, and compliant with regulatory requirements.Manufacturing: Software systems are used in manufacturing to control production processes, monitor equipment performance, and manage inventory. Effective software system design ensures that these systems are integrated, efficient, and reliable.Transportation: Software systems are used to manage logistics, track shipments, and optimize delivery routes in the transportation industry. Software system design ensures that these systems are reliable, secure, and able to handle large volumes of data.

In general, software system design is important in any industry where software applications are used to manage complex operations, automate processes, and optimize performance. Effective software system design ensures that these applications are reliable, efficient, and user-friendly, ultimately leading to improved business outcomes.

Summary

In this chapter, we explored the importance of system design and its role in developing software solutions that meet both functional and non-functional requirements. System design involves defining the architecture, components, modules, interfaces, and interactions of a software system. By effectively translating requirements into a well-structured blueprint, system design forms the foundation for successful software development.

We discussed two types of system design: high-level and low-level. High-level system design encompasses critical aspects such as system architecture, data flow, scalability, and fault tolerance. Conversely, low-level system design focuses on implementation details and specific components. Throughout the design process, a set of design documents is produced, serving as valuable blueprints for the actual implementation of the software system.

The significance of system design in the industry cannot be overstated. It promotes a clear understanding of requirements, facilitates collaboration, enables thorough design reviews and feedback, and ensures scalability, performance, and maintainability. Furthermore, well-designed systems contribute to efficient and cost-effective development while reducing the risk of errors and rework. Industries such as finance, e-commerce, healthcare, manufacturing, and transportation particularly benefit from effective software system design, as it empowers them to manage complex operations, automate processes, and optimize performance, ultimately driving improved business outcomes.

Looking ahead to the next chapter, we will delve into the methodologies and techniques employed during the system design process. We will explore practical approaches to translating requirements into well-designed software systems, equipping readers with valuable insights and strategies to enhance their system design capabilities.