Josh Karper
Founder at Stealth Startup
San Francisco, California, United States
Summary
👤
Senior🎓
Top SchoolJosh Karper is a founder and software engineer with nine years of experience building backend systems and payments-related infrastructure in the San Francisco Bay Area. He has driven 0-to-1 backend work and API design at Affirm, helped unify machine learning systems and scheduling payments at Cash App using Java/Kotlin/Go, and now leads a stealth startup. His background spans startups and enterprise (OpenPoll, Capital One) with hands-on work across Kotlin, Python, TypeScript, Go, and Ruby on Rails, focused on shopping, retention, and reliability. Josh has a practical mix of product-facing feature delivery and platform reliability—shipping in-app feeds, notification centers, and critical telemetry for leadership dashboards. He’s comfortable translating ambiguous product needs into production services and has experience operationalizing ML pipelines across teams. Based in San Francisco with a BS in Computer Science from the University of Maryland, he blends entrepreneurial drive with a track record of turning prototypes into scalable systems.
9 years of coding experience
9 years of employment as a software developer
Bachelor of Science - BS Computer Science, Bachelor of Science - BS Computer Science at University of Maryland
Github Skills (52)
mongoid10
transition10
user-feedback9
twitter-api9
fsm-library9
hotel-booking9
state-machine9
activemodel9
database8
mongodb8
api8
typescript8
java8
aasm8
twitter8
Programming languages (6)
Github contributions (5)
josh-ua/josh-ua.github.io
Oct 2016 - Dec 2023
personal site
Contributions:8 PRs, 91 pushes, 11 branches in 7 years 3 months
reactnextjs
josh-ua/earthquake-webgl-globe
Oct 2016 - Nov 2016
Contributions:53 commits, 16 PRs, 53 pushes in 19 days
globewebgl-globewebgldisplaysjavascript
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.