Lobsters is a production-grade Ruby on Rails application powering the social news aggregation and discussion site lobste.rs. It provides a full-featured platform for submitting, voting, commenting, and moderating links, with a focus on computing and technology topics. The architecture follows standard Rails MVC patterns with a rich set of controllers, models, views, mailers, and background jobs, using SQLite in production with SolidQueue for job processing and SolidCache for caching. The codebase emphasizes self-hosting, minimal external dependencies, and optional JavaScript, with a strong moderation system featuring hats, flags, bans, and a detailed moderation log. Key features include story submission with duplicate detection, threaded comments with Reddit-style confidence sorting, tagging and filtering, user invitations, private messaging, mod mail, full-text search, RSS feeds, and Fediverse integration via Mastodon. Authentication supports bcrypt, TOTP two-factor, and OAuth (GitHub, Mastodon). The application includes extensive test coverage with RSpec, factory_bot, and VCR for external HTTP interactions, and employs custom monitoring and security measures such as IP spoofing protection, rate limiting (Rack::Attack), and SSRF protection in its HTTP client. While primarily a standard Rails application, it contains several well-crafted, reusable components such as a custom HTTP client with SSRF protection, a Markdown renderer with username linking, and reusable concerns for token generation and username validation. The codebase is actively maintained with regular commits, though it acknowledges some 'dusty corners' and technical debt, such as inline partial duplication and a few brittle deployment-specific configurations. Overall, it is a solid, well-structured application that demonstrates good Rails engineering practices.