Data scientist and marketplace builder. I've spent 7+ years across fraud analytics, search relevance, computer vision/OCR, and product analytics — and I also operate in marketplaces directly: I founded a profitable multichannel vintage business and built the seller tooling behind a Whatnot operation doing $250K+/month in gross sales.

What I'm building now

• Yanni — photo-first inventory management and point-of-sale platform for vintage resellers (Next.js/TypeScript · Prisma · Supabase Postgres + pgvector · Stripe · FastAPI ML sidecar running OpenCLIP + pHash). Source is private; see the technical case study.

** Background highlights**

• Led a commercial AI check-fraud platform (YOLOv7, Siamese networks, multi-engine OCR) from prototype through pilot and production handoff
• Built explainable fraud & anomaly detection over 2M+ bank transaction rows (Python, SQL, GMMs)
• Improved enterprise search (Apache Solr) for a platform serving 10,000+ employees
• Designed the bulk listing/inventory pipeline behind a high-volume Whatnot live-selling operation

Reach me: johannpiedras.com · yanni.app