Callbacks are great for quickly tapping into the object life cycle. However, after a model or an application grows, it will become harder to maintain over time. It is better to extract the responsibility and separate the logic.

Keeping client data protected is important, but once an attribute is encrypted, it becomes difficult to work with it. With Blind Index, we regain functionality on searching and validations.

In this episode, we look into creating a blockchain as well as proof of work for car maintenance tracker application. Blockchain is used to establish a trust that records have not been tampered with.

Advancing from Single Table Inheritance, learn how Polymorphic Associations differ and tricks to simplify their usage.

Learn to use single table inheritance to allow multiple classes to be stored in the same database table.