Software engineer at CoStar Group
I am John ;)I am John ;)
Software Engineer, Hooper, and Rock climber located in Irvine. During the day I am a software engineer @ Costar group helping out with the E commerce experience behind Loopnet ads. At night I like to build apps that help make life a little easier. When I am not sitting at a desk I like to pretend I am Alex Honnold and also Steph Curry.
Experience
Where I've worked.
Current · Jul 2023 to Present
Full-stack Software Engineer, CoStar Group
E-Commerce team
- Re-architected a Hangfire job into a scalable .NET Background Service, raising throughput 46x from 173 to 8,000 listings per minute.
- Led the migration of LoopNet ads to Stripe, covering $4M in annual gross sales across 11,000+ accounts.
- Cut pricing API response times by 95% with Memcached and Redis caching.
- Used 63% fewer engineering hours (195 of 310) on a spec-driven modernization to React 19, TypeScript, and Vite with Claude Code.
- Built a Claude Code agent skill that the whole team adopted.
- Built a price-change detection system that enabled $461,160 in annualized revenue.
Projects
Things I'm building.
Side project · Private beta
Bankr
An AI-first personal finance app that shows its work.
- Every dollar figure in a chat answer is cited, and uncited figures get flagged.
- A nightly eval run checks answers against a hand-verified golden ledger.
- The agent proposes changes. You confirm them.
Building in public
What I've been shipping.
My GitHub activity over the last year.
54 contributions in the last year
Let's talk.
I'm always happy to hear about interesting problems, especially in payments, fintech, or AI products.