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Patrick McMahon

@patrickmcmahon

Product Engineer at PartsTown and Centriq who led a React Native migration and launched an open-source coaster leaderboard.

United States

Message

I launched CoasterRank, an open-source community leaderboard for roller coaster enthusiasts, using React, TypeScript, and Supabase. I optimized its ranking model and built it to support 1,000+ users on free platform tiers.

At PartsTown / Centriq, I led a migration to a multi-platform React Native stack and led a service-scheduling vertical across the mobile app and an embeddable web widget. Earlier, I worked on Hipcamp’s trip-search and booking rewrite and a product recommendation system for Staples.com that generated $9.3M in annual attributable revenue.

Experience

Work history, roles, and key accomplishments

Current

Freelance Technical Consultant

Current

Self Employed

Jan 2025 - Present (1 year 9 months)

Agentic development, local model fine-tuning, and voice-driven prototype exploration. Launched CoasterRank, an open-source community leaderboard.

Agentic Workflows Prompt Engineering Model Fine Tuning React TypeScript Supabase Cloudflare Workers CI CD

Senior Software Engineer

PartsTown / Centriq

Jan 2023 - Jan 2025 (2 years)

Led migration to a multi-platform React Native stack and introduced analytics and A/B testing. Led new service scheduling vertical.

React Native iOS Android Web Analytics A B Testing Mobile Development

Senior Software Engineer

Hipcamp

Jan 2021 - Jan 2023 (2 years)

Completed full rewrite of trip-search and booking experience from Rails to Next.js. Optimized performance and saved campgrounds feature to increase engagement.

Next.js Ruby on Rails Performance Optimization SEO Lighthouse Tile Based Loading

Mobile Team Lead

Centriq Technology

Jan 2018 - Jan 2020 (2 years)

Migrated legacy iOS app to React Native and grew mobile team from one to four developers. Improved app store ratings through user feedback integration.

React Native iOS Android Team Leadership Hiring Mentorship

Principal Software Engineer

Staples

Jan 2016 - Jan 2018 (2 years)

Primary product recommendation system for Staples.com, handling 1,500+ req/s and generating $9.3M in annual revenue. Developed internal webapp for real-time configuration and A/B testing.

Recommendation Systems A B Testing Web Applications High Traffic Systems

Frontend Developer

Honey

Jan 2016 - Dec 2016 (11 months)

Built first automated dev environment and automated testing of coupon scraping to detect failures immediately.

Automation Testing Frontend Development

Lead Frontend Developer

Roomstorm

Jan 2014 - Jan 2015 (1 year)

Second engineering hire, delivered React SPA as first public-facing product. Built white-label variant and set up first end-to-end tests and automated CI/CD.

React SPA White Labeling E2E Testing CI CD