Preface

Modern software is driven by users wanting new features, with no defects, released rapidly – a very challenging task. Solo developers have given way to development teams working together on a single software product. Features are added in short iterative cycles, then released to production frequently – sometimes daily.

Achieving this requires excellence in development. We must ensure that our software is always ready to be deployed and free of defects when it is released into production. It must be easy for our developer colleagues to work with. Code must be easy for anyone to understand and change. When the team makes those changes, we must have confidence that our new features work properly and that we have not broken any existing features.

This book brings together proven techniques that help make this a reality.

Test-driven development (TDD), the SOLID principles, and hexagonal architecture enable developers to engineer code that is known to work and known to be easy to work with. Development focuses on the fundamentals of software engineering. These practices are the technical foundation behind a code base that is easy and safe to change and always ready to be deployed.

This book will enable you to write well-engineered, well-tested code. You will have confidence that your code works as you think it should. You will have the safety of an ever-growing suite of fast-running tests, keeping a watchful eye over the whole code base as the team makes changes. You will learn how to organize your code to avoid difficulties caused by external systems such as payment services or database engines. You will reduce your dependence on slower forms of testing.

You will be writing higher quality code, suitable for a Continuous Delivery approach.

Modern software requires a modern development approach. By the end of this book, you will have mastered the techniques to apply one.