What should be in a contract with a Shopify developer?

At minimum: the scope and deliverables in plain language, the fixed price and payment schedule, the timeline, the number of revision rounds included, and — critically — a clause stating you own the final code and assets on full payment. Add what happens if either side cancels (a stop-cost per milestone), and an NDA if your project is sensitive.

Also pin down access (who holds the store/credentials), post-launch support terms, and who's responsible for third-party app/subscription costs. Most disputes come from fuzzy scope and unclear ownership — nail those two and you avoid the common headaches.