Live freight pricing at checkout, for 30,000 lb car lifts

A Shopify CarrierService that prices freight live at checkout. ArcBest LTL for the heavy items, UPS for parcels, quoted in the cart in real time. It runs as a long-lived TypeScript service on Railway rather than serverless, because its in-memory rate cache needs a process that stays up. It is health-checked every 60 seconds and critical failures go out as text alerts.

The rails around it. Before any customer saw it, I found 16 products carrying placeholder 99 lb weights. Left alone, a 30,000 lb lift would have quoted $355 instead of about $795. That is the kind of bug you only find if you go looking, and it never reached a customer.

An admin and warehouse console that is the source of record for every freight rate, built in Next.js on PocketBase.

A catalog launch that could not break checkout. 5,281 products across 77 collections went live. While staging it I found that publishing before shipping was configured would have blocked every mixed cart on the live store, a lift and a box of bolts together. The fix was the stage order, enforced in code so nobody can run it out of sequence.

A product page builder. The owner designs a page in the admin and it renders on the Shopify theme within 1 px of the admin at phone, tablet and desktop widths. It is live on the first lifts, with 1,196 automated tests passing in the admin codebase at sign-off.

Data cleanup with sign-off. Duplicate and placeholder spec fields cleared out and thousands of sheet values imported, all with the owner's sign-off.

A prototype AI product assistant that never invents a spec. The model does not state a number. It calls a function that knows the number.