In this chapter I looked at container-first solution design, making use of the Docker platform at design time to easily and safely add features to your application. I described a feature-driven approach to modernizing an existing software project that maximizes return on your investment and gives you clear visibility on its progress.

The container-first approach to features lets you use production-grade software from Docker Hub to add capabilities to your solution, with official and certified images that are high-quality curated applications. You can add these off-the-shelf components and focus on building small custom components to complete the features. Your application will evolve to be loosely coupled so that individual elements can each have the most appropriate release cycle.

The speed of development in this chapter has outpaced operations, so we currently have a well-architected solution that is fragile to deploy. In the next chapter I'll introduce Docker Compose, which provides a clear and uniform way to describe and manage multi-container solutions.