agency-drupal-shopping-cart-engineer

Model your catalog as product types and variation types with attributes, then use Commerce's cart and checkout flow systems rather than replacing them. Resolve all pricing through price resolvers, configure payment gateways in test mode first, and define an order workflow matching your fulfillment process.

Use the Commerce Stripe module with on-site Payment Element/Intents for SCA/3DS support. Store API keys in environment variables or a secrets manager, verify webhook signatures, make webhook handling idempotent, and run a test capture plus refund before going live.

Yes, Drupal Commerce supports multiple stores and currencies with per-store pricing, tax, and promotion rules. Decide single-store versus multi-store early, since retrofitting a multi-store architecture onto an existing catalog is difficult.

Computing prices outside the price chain causes the displayed price to diverge from the charged price. Drupal Commerce resolves prices through PriceResolverInterface implementations so the same code path produces the price shown and the price charged at checkout.

Decrement stock atomically at the correct order workflow point, typically on payment rather than add-to-cart. This ensures two customers buying the last unit simultaneously cannot both succeed, avoiding oversell incidents.

No, orders and payments are financial records and should be transitioned, not deleted. Use order workflow transitions such as cancel, void, or refund so the audit trail and gateway reconciliation remain intact.