Princess Auto — payments & checkout
Payment integration and checkout for Princess Auto — the Canadian retail brand. Connecting and configuring the payment stack for secure, reliable transactions at scale.
Boring payments are the best payments
The job wasn't to reinvent checkout — it was to make sure every transaction lands cleanly, every refund threads, and every state survives a retry.
Princess Auto is a Canadian retailer specialising in tools, automotive parts, industrial equipment and hardware, serving DIY enthusiasts, tradespeople and professionals.
We owned the payment integration end to end: server-side intents, the client-side checkout flow, webhook handlers for async settlement, and the dashboard plumbing that lets ops see what's stuck. The work was the unglamorous half of e-commerce — idempotency keys, webhook reconciliation, refund handling, and the surface where a storefront meets a checkout SDK.
A storefront with payments wired through
Catalog, promos, flyers, and a basket flow — on top of a checkout backend that doesn't lose money on a flaky connection.
What we built
Server-authoritative intents and retries
Every payment is initiated server-side with an idempotency key tied to the cart hash. Retries from a flaky client don't double-charge; webhook reconciliation closes the loop.
- —Server-side payment intents with idempotency keys
- —Cart-hash-bound retry semantics
- —Webhook-driven settlement reconciliation
Pickup + ship-to-home in one flow
Store-pickup and shipping share the same intent model, so refunds and partial captures behave the same regardless of fulfillment path — with per-SKU availability surfaced right in the checkout.
- —Pickup + ship-to-home in one checkout
- —Idempotent basket and intent semantics
Refunds that survive partial fulfillment
Online plus store-pickup means partial fulfillment is the norm. Refunds are processed against the same intent model so accounting stays clean across split shipments.
- —Partial + full refund support
- —Reconciles across store-pickup and ship-to-home
- —Accounting export with per-line tax + fees
More screens
More cases
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