Trix is rich text editor that's easy to install and use if you're looking for a quick solution.
You can use it with Ruby on Rails or React.
Good overview of Domain Driven Design: https://blog.thelonearchitect.com/a-gentle-introduction-to-domain-driven-design-dc7cc169b1d.
The team behind Hanami explaining the general idea behind the architecture for their framework: ...
Good explanation of how the include method works in ActiveRecord queries: https://longliveruby.com/articles/includes-method-in-rails.
RabbitMQ is a popular message broker software.
If you're using RabbitMQ in ruby/rails, consider using the bunny library for publishing messages...
Good high level overview of REST, GraphQL, and gRPC: