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Repricing Engine

Daily competitive repricer across thousands of SKUs with rule-based guardrails. Tracks margin floor, buy-box position, and competitor velocity to keep pricing honest without eroding profit.

Year
2025
Context
JS Labs
Role
Design, engineering, and operations
Stack
Next.jsSupabaseVercel CronMarketplace APIs

01 — The Challenge

Manual repricing can't keep up with competitor moves across thousands of SKUs, but naive auto-repricers create a worse problem: they race each other to the bottom and quietly destroy margin. The job isn't to always be cheapest — it's to hold buy-box position where it's profitable and walk away where it isn't.

02 — The Approach

A daily batch repricer built on explicit rules rather than a black box. Every SKU carries a margin floor computed from real costs — fees, fulfillment, FX — that no rule can cross. Above the floor, rules weigh buy-box position and competitor velocity: how fast rivals are moving, not just where they are. When the engine wants to do something unusual, it doesn't — it flags the SKU for a human instead.

03 — What I Built

A rule system with hard guardrails: margin floors computed per SKU from fees, fulfillment cost, and FX, enforced before any price is published

Buy-box and competitor tracking that feeds velocity signals — direction and speed of competitor moves — into the daily pricing decision

Daily batch runs on Vercel Cron with full pricing history in Supabase, so every price change is explainable after the fact

An exceptions queue: SKUs where rules conflict or competitors behave strangely get routed to a human instead of guessed at

04 — The Outcome

Pricing across thousands of SKUs stays competitive without anyone watching a spreadsheet, and the guardrails guarantee no price ever ships below its margin floor. The team's pricing work shrank to reviewing a short exceptions list each morning.

Daily runsMulti-SKUMargin floors

Want something like this built for you?

I take on a small number of builds like this each year — agentic systems and tooling for marketplace teams.

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