How to measure where time goes during Rubree's WASM Rails boot sequence (Service Worker → ruby.wasm), and what we already learned from one full measurement pass — gem require + Rails.application.initialize! + WASM compile dominate (~99%), while the ActiveRecord DB adapter (sqlite3_wasm vs nulldb) is negligible (~1.5%). Use when investigating "WASM load is slow", "the page freezes on iOS/mobile while loading", or when considering swapping the DB adapter to speed up boot — measure first, this skill shows how and what was already found.
How Rubree's local setup (.devcontainer/setup.sh), CI (ci.yml), and Deploy (deploy.yml) connect — dotfile-driven tool versions, WASM build caching, Dependabot grouping/auto-merge, Lefthook hook scope, and the Chrome/Edge-only browser support constraint. Use when changing CI/CD workflows, the devcontainer, dependency automation, or anything that touches the WASM build or deploy pipeline.
Why Rubree models domain logic as ActiveModel-based POROs in app/models instead of service objects or form objects, how classes get named and split up, and why coverage is visualized. Use when adding new domain logic, deciding where new code should live, naming a new class, weighing whether to introduce a service or form object, or reviewing a PR or diff. For frontend conventions (Alpine.js, Stimulus, Turbo, ERB, SVG), see the frontend-patterns skill.
Rubree's frontend conventions — when to use Alpine.js vs Stimulus, how Turbo Frame and form submission work, ERB whitespace rules for preformatted output, inline helper methods, and SVG safety. Use when writing or reviewing Stimulus controllers, Alpine.js components, ERB templates, Turbo Frames, or anything that touches the client-side rendering pipeline.
Create and follow a .steering/ task plan for work expected to span multiple sessions or requiring a design decision before implementation. Use when starting a feature, a non-trivial refactor, or any task where you'd otherwise lose context between sessions.
Conventions for writing, organizing, and running RSpec tests in Rubree — spec layout, description style, mocking, system-spec driver selection, and the octocov coverage/ratio/time thresholds enforced on every PR. Use when writing or reviewing specs, deciding which spec layer (model/request/system) to use, or wondering why a PR's coverage check failed.