In the past, the software industry was focused on developing software at high speed, with nothing in mind but cost and time. Quality was a secondary goal, with the false feeling that customers were not interested in it.

Nowadays, with the increasing connectivity of all kinds of platforms and devices, quality has become a first-class citizen in customer's requirements. Good applications offer a good service with a reasonable response-time, without being affected by a multitude of concurrent requests from many users.

Good applications in terms of quality are those that have been well designed. A good design means scalability, security, maintainability, and many other desired attributes.

In this chapter, we will explore how TDD leads developers to good design and best practices by implementing the same application using both the traditional and TDD approaches.

The following topics will be covered in this chapter:

• Why should we care about design?
• Design considerations and principles
• The traditional development process
• The TDD approach using Hamcrest