Dynamic pricing engine for a clinical laboratory network
A multi-tenant pricing engine that calculates test-panel prices in real time from reagent cost, overhead, organisation-specific contract terms and revenue share rules, with full audit history and Excel round-tripping for commercial teams.
The challenge
The same clinical laboratory group had a pricing problem. Test-panel pricing depended on dozens of moving parts: the composition of each panel, reagent cost, per-organisation discounts, overhead models, donation accounting and revenue-share agreements with referring networks. All of it lived in spreadsheets that were edited, emailed and forgotten about. When a pricing dispute came up, nobody could reconstruct how a given price had been calculated.
They needed a pricing engine that commercial teams could actually trust: every quote had to be reproducible, every rule change had to be auditable, and every pricing decision had to be defensible if a regulator or an auditor ever asked.
Our approach
- Modelled the pricing domain explicitly: tests, panels, organisations, contracts, discount rules, overhead models, revenue shares. Every entity versioned, every rule change attributable.
- Built a Next.js full-stack application with a clean internal API so the pricing logic could be called both from the dashboard and from downstream systems.
- Added Excel import and export so commercial teams could continue using their spreadsheet workflow while the engine remained the single source of truth.
- Wrote 160+ automated tests (unit, integration, end-to-end) covering the edge cases the commercial team had spent years fighting — so any future change would fail loudly if it broke a known scenario.
Architecture highlights
- Next.js 15 App Router on TypeScript, with server-side validation via Zod
- PostgreSQL schema modelled in Prisma, with versioned pricing rules
- NextAuth for authentication and role-based access
- ExcelJS for round-tripping the client's existing spreadsheet format
- Vitest + Playwright for unit and end-to-end test coverage
- Audit log recording every price quote and every rule change with full reproducibility
Outcome
- Every pricing decision reproducible from the stored inputs, no matter how far in the past
- Commercial team workflow preserved — Excel in, Excel out — while the engine owns the math
- 160+ automated tests covering panel composition, discount stacking, revenue share and overhead edge cases
- Pricing disputes resolved by replaying the audit log rather than guessing
Let's build something that ships.
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