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I help teams build and scale Rails applications — from architecture decisions to production performance.

What I can help with

Rails architecture & performance Dealing with a slow Rails app, a tangled codebase, or a migration that feels risky? I’ve spent 12+ years untangling these problems in production.

GraphQL API design Schema design, performance optimization, and best practices. I created rubocop-graphql, a linting toolset with 43M+ downloads used by teams worldwide.

LLM integration in Rails Building AI features into an existing Rails application — multi-provider setups, RAG pipelines, observability, and agent integrations.

Production readiness for AI-built apps Built your app with Claude or ChatGPT and hitting the limits of what AI can help with? I can audit your codebase and get it ready for real users.

How I work

  • One-time audit — I review your codebase, identify the most critical issues, and deliver a prioritized report.
  • Short engagement — focused work on a specific problem over 2–4 weeks.
  • Ongoing advisory — available for questions, architecture reviews, and code feedback on a monthly retainer.

Why me

  • 12 years building Rails backends in production
  • Creator of store_model, ar_lazy_preload, and rubocop-graphql — 50M+ downloads total
  • Contributor to Ruby, Rails, and graphql-ruby
  • Conference speaker and technical blogger

Get in touch

Email: dmitry.a.tsepelev@gmail.com

Telegram: @dmitry_tsepelev