rails/fullstack / learn

Short problem→reveal cards across six categories. Spot the Tax, Reading the Source, Scaling, SOLID, Payments, and Interview Prep. Commit to an answer before any explanation appears.

Plain-language walkthroughs of how Rails actually works. Twelve lessons covering routing, queries, rendering, params, callbacks, forms, and the model declarations you use every day.

The five SOLID principles, 19 lessons. Each anchored in production code from Mastodon, Forem, Discourse, Gumroad, and Rails core.

Eight lessons on diagnosing and fixing the bottlenecks every Rails team hits. Where the bottleneck actually lives, the order to fix things in.

Six lessons on building payments into a Rails app the way real teams do it: payment intents, idempotency, webhooks, async confirmation, refunds, and the ledger pattern.

How senior Rails interviews actually work, system-design framing, behavioral stories, and the modern-stack questions (Solid Queue, Hotwire, Kamal) interviewers ask in 2026.

Where the senior gap lives in modern Rails frontends. Turbo Streams vs Broadcasts, lazy Frames, Stimulus boundaries, Rails 8 morphing, and the honest call on when to graduate to a real framework.

Running Postgres under a Rails app. Reading query plans, indexing beyond btree, window functions and CTEs, vacuum and bloat, transaction isolation, zero-downtime migrations, and read replicas.