Certificate

# ===== Award criteria =====
# Pass: >= 70%; Distinction >= 85%.
#
# 1. Project structure        (10)
# 2. Ruby idioms              (15)
# 3. Rails app (or Sinatra)   (15)
# 4. ActiveRecord + migrations (15)
# 5. Tests + factories         (15)
# 6. Background jobs + mailers (10)
# 7. Deploy + CI               (10)
# 8. Communication             (10)

# ===== Project brief =====
# Ship a small Rails app with:
# - Real domain (todo, blog, mini-shop, jobs board)
# - 4+ models with associations + validations
# - Authentication (Devise) or session login
# - At least 1 background job (Sidekiq + Redis)
# - At least 1 mailer (with preview)
# - 70%+ test coverage (RSpec + factory_bot + Capybara)
# - Deploy to Render / Fly.io / Heroku / Railway
# - GitHub Actions CI (rubocop + tests on every PR)
# - README with screenshots + architecture

# ===== Sample structure =====
# shop/
#   app/
#     models/
#     controllers/
#     views/
#     jobs/
#     mailers/
#     services/
#   config/
#     routes.rb
#     environments/
#   db/
#     migrate/
#     schema.rb
#   spec/
#     models/
#     requests/
#     features/
#     factories/
#   Gemfile + Gemfile.lock
#   .github/workflows/ci.yml
#   bin/setup
#   README.md

# ===== Marking sheet (example) =====
# 1. Structure          9/10   service objects, no fat models / controllers
# 2. Idioms            13/15   blocks, frozen strings, scopes, concerns
# 3. Rails app         14/15   resourceful routes, partials, helpers
# 4. ActiveRecord      13/15   associations + validations + scopes; no N+1
# 5. Tests             13/15   request + feature + system specs, factories
# 6. Jobs + mailers     9/10   Sidekiq with retry; mailer previews
# 7. Deploy + CI        9/10   GitHub Actions, deploy script, smoke test
# 8. Communication      9/10   README, screenshots, runbook
# Total: 89/100 -> Distinction

# ===== Patterns to internalise =====
# - REST + resourceful routes
# - includes / preload to avoid N+1
# - Service objects + concerns for fat-model fixes
# - Strong params; never permit!(:all)
# - Background jobs for anything > 100ms
# - frozen_string_literal: true on every file

# ===== Pitfalls =====
# - Mass assignment bugs (always strong params)
# - SQL injection via string interpolation in where()
# - Sending email synchronously in a controller
# - Long migration that locks tables on deploy
# - Forgetting to scope queries by current_user

# /certificate/ruby