Building Secure and Reliable Systems

Chapter 12. Writing Code

By Michał Czapiński and Julian Bangert

with Thomas Maufer and Kavita Guliani

Code will inevitably include bugs. However, you can avoid common security vulnerabilities and reliability issues by using hardened frameworks and libraries designed to be resilient against these problem classes.

This chapter presents software development patterns that should be applied during the implementation of a project. We start by looking at an RPC backend example and exploring how frameworks help us automatically enforce desired security properties and mitigate typical reliability anti-patterns. We also focus on code simplicity, which is achieved by controlling the accumulation of technical debt and refactoring the codebase when needed. We conclude with tips on how to select the right tools and make the most of your chosen development languages.

Security and reliability cannot easily be retrofitted into software, so it’s important to account for them in software design from the earliest phases. Tacking on these features after a launch is painful and less effective, and may require you to change other fundamental assumptions about the codebase (see Chapter 4 for a deeper discussion on this topic).

The first and most important step in reducing security and reliability issues is to educate developers. However, even the best-trained engineers make mistakes—security experts can write insecure code and SREs can miss reliability issues. It’s difficult to keep the many considerations ...