Ronn Tan.
Software Engineer & Founder.

Snap a photo, get an instant identification and real-time pricing across 100+ retail and resale marketplaces. Built end-to-end as a solo founder — backend, ML pipeline, scraping infrastructure, payments, and App Store launch.

• Multi-source price estimation engine combining Gemini (vision + language), eBay sold data, retail waterfalls, and outlier-filtered aggregation.
• Two-layer Redis + MongoDB caching with canonical key matching and vector similarity fallback — sub-second repeat lookups, dramatically lower LLM costs.
• Core ML for on-device image similarity; Gemini embeddings + vector search for fuzzy title matching across a growing catalog.
• Production Next.js backend on Railway with a real-time scraping pipeline using Decodo residential proxies and Cloudflare R2 storage.
• StoreKit 2 subscriptions, RevenueCat, and eBay Partner Network affiliate — full App Store submission and review.

Progressed from junior engineer to Lead, owning backend architecture and data systems for a high-scale people-search platform serving hundreds of millions of records and millions of daily queries.

• Led a zero-downtime migration of the entire production platform from on-prem to AWS as the sole engineer — re-routing live traffic and modernizing compute, storage, and CI/CD while reducing infrastructure costs.
• Architected data models across MongoDB and MySQL supporting hundreds of millions of records and millions of daily queries.
• Designed event-driven queueing and async processing systems for high-throughput data ingestion and search at scale.
• Leveraged AWS Lambda to offload background workloads and automate large-scale data pipelines, reducing compute costs and latency.
• Built real-time APIs, internal tools, and user-facing portals; owned production reliability, performance, and scalability.

Point your camera at an OOTD — yours, a stranger's, a screenshot — and instantly identify every piece of apparel, accessory, and footwear in the frame. Cross-marketplace lookup tells you where to buy and what each item costs right now.

• Same identification + pricing pipeline as Appraiso, retargeted to fashion (apparel, accessories, footwear)
• Cross-marketplace lookup across 100+ retailers — Nordstrom, Farfetch, Grailed, eBay, etc.
• Save outfits to a closet, get price-drop and restock alerts on the items you want
• Built as a thin product layer on top of the Appraiso engine — proves the platform thesis