Joe Sak

Senior Rails Engineer in Denver

I make hard-to-change software maintainable.

Full-stack by history, Rails by habitat. I care about readable code that is easy to test and change. I'm most useful when an AI-built or vibe-coded prototype needs to become a real product the next engineer can trust.

Portrait of Joe Sak
Senior Rails engineer, platform caretaker, and software craftsmanship mentor.

Now

Developer Productivity Rails L3 Staff Engineer at Gusto.

Useful For

Maintainability, Rails modernization, repository health, technical debt strategy, AI prototype rescue, user-minded product work, and mentorship.

Contact

Email me
LinkedIn
Resume

Selected Work

Maintainability at scale.

Maintainability

Turning prototypes into code teams can own

Vibe-coded projects prove an idea quickly. I turn them into systems people can read, test, and change: clear names, real boundaries, dependencies under control.

Gusto

Rails upgrades across monoliths and services

Upgraded Gusto's two Rails monoliths to 8.0 and 8.1, and raised the extracted services to a 7.2 minimum. The oldest had been sitting on Rails 6.0.

Productivity

A maturity model for technical debt

Built scorecard tooling to campaign and track repo upgrades across Ruby, Rails, Rubocop, Sorbet, Appraisal, and related standards, with an automation plan for Ruby and Rails EOL windows.

Architecture

Service separation and safer rollouts

Contributed to monolith extraction and GraphQL federation for centralized feature flags, service decoupling, and progressive delivery.

Mentorship

Software craftsmanship without mystique

Mentor small cohorts of apprentices through code review, pairing, fundamentals, and honest career advice.

Legacy Apps

Big upgrades on systems people depend on

In 2021, migrated Kadenze from Rails 4.2 and Ruby 2.3 to Rails 6.1 and Ruby 2.7. In 2024, led MemberSpace's Rails 6 and Ruby 2.x modernization toward Rails 8 and Ruby 3.4.

From Teammates

What teammates say.

Judgment

"Joe has a real talent for diving into complex challenges and finding effective solutions."

I'm at my best on tangled, important problems that need real judgment, not a quick patch.

Reliability

"His reliability and drive made him a key part of our team."

People have trusted me with production infrastructure, data security, upgrade paths, team protocols, and systems that need to keep working.

Product

"He built our custom web app from scratch."

That product served tens of thousands of users across more than 100 countries, with separate paths for students, mentors, judges, volunteers, and administrators.

Users

"Joe always had the needs of our users in mind."

That meant rural and remote access, low-income communities, children, and users at very different levels of technical comfort.

Rollouts

"Standby revert PRs being open and ready before each deploy was a small but high value choice."

My upgrade work comes with rollback planning, timing updates, and real-time triage when production changes ripple across services.

Ownership

"He took the reins and drove the project forward."

Peers highlighted initiative on feature flag GraphQL work, generator tooling, service extraction, incident response, and tricky codebase problems.

Support

"I consistently learn from you in our interactions."

Feedback repeatedly mentions patience, helpfulness, pairing, documentation, and making Ruby and Rails work easier for product engineers.

Craft

"Joe is an asset to any team."

What it adds up to is maintainable work: readable code, practical architecture, careful refactoring, and systems other people can understand and change.

What I Know

Tools I use to keep code easy to change.

Application

Ruby, Rails, Phlex, Hotwire, GraphQL, JavaScript, HTML, CSS, SEO, accessibility, RSpec, clean code, SOLID object design, patient refactoring, and product-minded UI work.

Platform

PostgreSQL, Redis, Sidekiq, AWS, Heroku, Docker, Linux, OAuth, APIs, service integrations, infrastructure ownership, data security, technical planning, and mentorship.

Experience

Places I've kept systems moving.

  1. 2024 - Now

    Gusto - Developer Productivity Rails L3 Staff Engineer

    Direct support, tooling, Rails upgrades, repo standards, feature flags, and technical debt strategy.

  2. 2021 - 2024

    MemberSpace - Senior Rails Developer

    Full-stack legacy migration, production infrastructure, uptime ownership, and clean-code refactoring.

  3. 2019 - 2021

    Kadenze - Lead Applications and DevOps Engineer

    Rails and Ruby upgrades, AWS and Docker operations, multi-tenancy, and education-platform portals.

  4. 2016 - 2019

    Iridescent / Technovation - Lead Web Developer

    Built a global product for 30,000+ users, five user types, and 120+ countries; shaped UI/UX around varied access needs and worked closely with non-technical teams.

  5. 2005 - 2016

    Freelance, InfoActive, Neoteric, Artemis

    Agency leadership, reusable Rails engines, test suites, sales demos, apprentice programs, team development, and client-facing delivery.

Elsewhere

Denver, streets, snow, and the rest of life.

I chair Denver's Mayor's Bicycle Advisory Committee, volunteer with Denver Streets Partnership, and helped restart Denver Critical Mass. I also like snowboarding, hiking, and Avalanche hockey.

Contact

Want to make a hard-to-change codebase easier to own?

Email is best: Email me. I'm good at taking messy, rushed, AI-assisted, or long-lived software and making it maintainable. You can also find me on LinkedIn and GitHub. Here's my resume.