Diagnosing slow ActiveRecord queries, N+1 issues, and performance mismatches between SQL and Rails, using real production examples.
Master Rails WHERE clause with multiple conditions, OR logic, and SQL strings. Learn WHERE vs HAVING and how to verify generated SQL with real examples.
Ruby 4.0.0 is released (Dec 25, 2025). For Rails apps, the real risks are stdlib gem changes (CGI), Net::HTTP behavior shifts, and Bundler 4. Here’s what breaks first, how to fix safely, and what Ruby 4 performance does—and doesn’t—solve.
A production-focused preview of Rails 8.2 explaining real-world impact on caching, TypeScript integration, Turbo behavior, and upgrade risks.