First service you use when you integrated with AWS is Identity and Access Management (IAM). This service manages permission of users/groups, resources and services under an AWS account. There are three type of IAM identity and have a relationship like the image:
At Jetabroad, we recently introduced SonarQube, a static analysis tool, into our development workflow. SonarQube finds bugs and "code smells" in our GitHub pull requests, and helps us keep our codebase clean. It's been a great, low-friction addition that's improved the quality of our code.