Overview
A highly resilient, hosted multi-tenant commerce engine delivering zero-friction tenant routing at the DNS layer via Vercel Middleware. It runs an intentional manual-first operational philosophy, such as manual receipt verification and courier assignment panels, built to share strict state-machine contracts and data models with future automation layers without schema disruption.
The Challenge & Solution
Multi-tenant commerce usually leaks between tenants and oversells during traffic spikes. We pushed isolation down to the database and made concurrency mathematically safe, so each tenant is sealed off and no product is ever sold twice, even during a high-pressure drop.
Architecture
An edge-optimised Next.js 16 and React 19 App Router architecture on a unified Supabase PostgreSQL engine, enforcing tenant security with database-layer Row Level Security. Cart operations use xmin-based optimistic concurrency and checkout commits use explicit pessimistic row-level locking to mathematically eliminate deadlocks and overselling during high-concurrency product drops.
Security & Scale
Tenant isolation is enforced at the database layer with Row Level Security rather than trusted application code, and the concurrency model is provably deadlock-free and oversell-free under load.
Telemetry & Outcomes
Full-scale observability with structured JSON logs and transactional trace IDs across edge instances via OpenTelemetry, a transactional Postgres outbox pattern to prevent lost notifications during network failures, exhaustive PostHog clickstreams, and edge-evaluated feature flags resolving within ~0ms.