Justin Marsh
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Hi there, my name is

Justin Marsh.

|

Available for opportunities

About Me

I enjoy creating things that live on the internet! My formal background is in mechanical design and my interest in web development started back in 2020 when I built my first web application — for a passion of mine, Argentine Tango.

Today, I'm the lead developer at Gaia Law, building AI-powered tools for contract and equity management. I'm product-focused and design-oriented—I believe beautiful code and thoughtful interfaces go hand in hand.

Justin Marsh

Technology

I believe in choosing the right tool for the job, not the newest or most popular one. My approach is to prioritize developer experience, maintainability, and user performance. I prefer proven technologies that enable rapid iteration and long-term stability.

Experience

  • Lead developer building the core product driving company revenue — an AI-powered platform for contract management and equity management
  • Architecting the full stack with Ruby on Rails, integrating AI capabilities for contract analysis and legal document processing
  • Collaborating directly with CTO to shape technical direction and product roadmap
  • Built Anymator from the ground up — a personalized video greeting card platform with a custom Blender rendering pipeline
  • Added high-concurrency event ticketing features to Krasser Stoff, handling real-time seat availability and checkout under load
  • Built search and discovery for Recordsale, the world's largest online vinyl store with 1,000,000+ records
  • Implemented recommendation algorithms and image recognition systems across client projects
  • Worked across Rails 7, Hotwire, PostgreSQL, Redis, React, TypeScript, and GraphQL
  • Upgraded legacy Rails applications and modernized frontends with Hotwire and Stimulus
  • Integrated external shipping providers to streamline order fulfillment workflows
  • Added retroactive system and integration test coverage to legacy codebases
  • Created a Shopify storefront for a fashion brand
  • Completed intensive Ruby on Rails bootcamp
  • Learned full-stack web development with Ruby, Rails, and JavaScript
  • Built multiple web applications as part of curriculum
  • Led manufacturing documentation for the Meta 2 augmented reality headset production run, creating all manufacturing drawings from frog design concepts
  • Designed high-density networking chassis for Juniper Networks including the MX2020, the industry's highest-capacity edge router
  • Developed medical instruments including the Sciton JOULE X laser platform and the IONpath MIBIscope
  • Managed full product lifecycle from concept through production with domestic and offshore manufacturers
  • Converted the Armadillo and Scorpion unmanned ground vehicles from prototype to production for law enforcement and military use
  • Designed injection-molded housings and cast aluminum chassis to Mil-Spec standards with IP65/IP67 ratings
  • Conducted Environmental Stress Screening (ESS) testing — vibration, thermal cycling, and drop testing for military qualification
  • Created technical drawings and assembly documentation for production

Featured Projects

These are projects where I was the lead developer and were built from the ground up.

Featured Project

Anymator

A video greeting card website built from the ground up. Features a custom Blender server for rendering personalized video/picture cards with user-provided text and images. Built entirely with Hotwire and Stimulus!

Ruby on RailsHotwireStimulusBlender
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Featured Project

TangoCloud

A progressive web app for organizing and discovering tango events. Fast, reliable, and mobile-friendly. Built for the global tango community.

Ruby on RailsHotwireStimulusFaceted SearchRecommendation AlgorithmsProgressive Web App
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Featured Project

TangoTube

A modern media streaming platform for tango dancers. Built with Ruby on Rails, React, and HLS streaming. Designed for high interactivity and seamless performance.

Ruby on RailsHotwireStimulusProgressive Web ApplicationPhlexHLS StreamingAudio VisualizationData EnrichmentAudio Recognition
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What's Next?

Get in Touch

Interested to work together? Or do you just want to meet and have a virtual coffee?

I love meeting new people. Let's chat!