Case Study: Critique This Architecture

1. The Question

*"A team hands you this design for their food-ordering startup (30 engineers). Twelve services: User, Order, Product, Payment, Cart, Review, Email, SMS, Address, Coupon, Wishlist, Analytics. All twelve share one PostgreSQL database 'for consistency.' Placing an order calls User, then Cart, then Product, then Coupon, then Payment, then Order, synchronously, in sequence. Payment calls are retried up to 5 times on any error. The API gateway checks whether users are premium members to decide which recommendation algorithm to call. Liveness probes check database connectivity