GraphQL enables clients to request exactly the data they need. The graphql-ruby gem implements GraphQL servers in Rails. Types define data structures—ObjectTypes for models, InputTypes for mutations. Queries fetch data; mutations modify data. Resolver

Value objects represent immutable domain concepts without identity. I use value objects for money, addresses, date ranges, coordinates. Value objects are compared by value, not identity—two identical addresses are equal. They're immutable—create new i

ActiveStorage handles file uploads with cloud storage integration. It supports local disk, S3, Google Cloud Storage, Azure. Files attach to models via has_one_attached and has_many_attached. I use ActiveStorage for avatars, documents, images. Image va

Draper decorators encapsulate view-specific logic, keeping models clean. Decorators wrap models, adding presentation methods without polluting domain logic. I use decorators for formatting, conditional rendering, helper delegation. Decorators access h

rack-mini-profiler reveals performance bottlenecks in Rails apps. It displays database queries, rendering time, memory allocation on every page. I use Flamegraphs to visualize where time is spent. Memory profiling identifies allocation hotspots. Query

Rack middleware processes HTTP requests/responses in Rails' stack. Middleware sits between web server and application, modifying requests before they reach controllers. I build custom middleware for logging, authentication, rate limiting, request modi

Pundit provides simple, object-oriented authorization. Policies encapsulate authorization rules in plain Ruby classes. Each model gets a policy class defining who can perform actions. I use Pundit for fine-grained permissions—different users see diffe

ActionCable integrates WebSockets seamlessly with Rails. Channels handle pub/sub messaging between server and clients. I use ActionCable for chat, notifications, live updates. Channels subscribe clients to streams; broadcasting pushes data to subscrib

Hotwire Turbo delivers SPA speed without JavaScript complexity. Turbo Drive accelerates navigation by replacing page body without full reload. Turbo Frames update page sections independently—click a frame link, only that frame refreshes. Turbo Streams

Query objects encapsulate complex database queries in reusable, testable classes. I use query objects when scopes become too complex or require parameters. Query objects compose smaller scopes, handle conditionals, and apply filtering logic. They're i

Form objects encapsulate form logic separate from models. I use form objects for multi-model forms, complex validations, or forms not directly mapping to models. Form objects include ActiveModel modules for validations and callbacks. They handle param

Rails migrations evolve database schema over time. I use change method for reversible migrations. Migrations create tables, add/remove columns, add indices. up and down methods provide explicit control. Irreversible migrations like data transformation