Concerns in Rails: Everything You Need to Know

API documentation often leaves the intent of the design as an exercise for the reader.

however, understanding the rationale and the complexity of the decision on when to use an API are critical to both education and adoption.

it would be neat if API documentation could link out to such resources to increase their discoverability and lend trust to the community.

Concerns are an important concept in Rails that can be confusing to understand for those new to Rails as well as seasoned practitioners. This post explains what concerns are, how they work, and how & when you should use them to simplify your code, with practical, real-world examples.