I decided to move my personal projects from Heroku to Docker. This was really useful in development, where each service has a bunch of dependencies.
Working with Docker Compose, I've created really useful development setups, including test environments.
After this, I worked on replicating it as part of my continuous integration tools, and running the tests in containers.
Finally, I spent a while working with the AWS EC2 Container Service (ECS) to create a simple process to deploy changes to production, including blue/green deployment.