Senior Ruby on Rails Engineer
Ship code confidently, from development to deployment.
I'm a fractional Ruby on Rails backend engineer helping small teams build reliable systems, escape expensive Heroku bills, and fix slow CI pipelines.
Services
Fractional Ruby on Rails Engineer
Join your team part-time to ship features, tackle tech debt, and keep your codebase healthy. No long-term commitment required.
Heroku to Kamal Migration
Move off Heroku without the headache, and cut your hosting costs 60-80%. I handle the full migration to Kamal on your own servers, with a clear runbook for your team.
CI Pipeline Optimization
Slow CI kills momentum. I'll audit your pipeline, parallelize your test suite, and get your builds shipping in minutes instead of hours.
Testing Audit
Your testing process should give you confidence, not slow you down. I audit Rails applications to help sort out test flakiness, bad patterns, performance bottlenecks, and gaps in your testing strategy, then give you a clear plan to fix them.
Hi, I'm Dennis Martinez
I've been building software for over 20 years, mostly backend systems in Ruby on Rails with a focus on the infrastructure and testing practices that keep teams shipping confidently. I've worked at startups in New York, San Francisco, Tokyo, and remotely worldwide.
What Clients Say
"Dennis is one of those guys who can do just about anything. We worked together on a tricky port of a Rails app from Heroku to Docker and he solved all of the difficult parts."
"We've benefited a lot from Dennis's skill in backend development, DevOps, automated testing, and CI/CD. His eye for detail has become the gold standard for our team."
"One of the best software engineers on our teams in terms of pragmatic problem solving, consistent communication, and on-time delivery."
Ready to ship faster?
Let's talk about how I can help your team.