Api Gateway

Prerequisite: Part 2 of the System Design Masterclass. Read Part 1: System Design Thinking first to understand foundational trade-off frameworks. Answer-first: L4 load balancing routes traffic by transport-layer (IP/TCP/UDP) metadata — minimal CPU overhead but limited intelligence. L7 load balancing inspects HTTP headers, paths, and cookies — enables content-based routing and advanced health checks at the cost of higher processing overhead per request. L4 vs L7 Load Balancing — The Definitive Comparison Answer-first: The fundamental difference is where in the network stack the routing decision is made. L4 (Transport Layer) routes at TCP/UDP level using IP+port tuples. L7 (Application Layer) routes at HTTP level using headers, URLs, and payloads. ...

← Previous | Series hub | Next → Chapter 6: Clarifying the Boundaries: API Gateway vs Service Mesh When your Golang application scales from dozens to hundreds of Microservices, managing communication becomes a macro-level challenge. You will constantly encounter two tightly coupled concepts: API Gateway and Service Mesh. Many engineers ask: “If I already deploy Istio (Service Mesh), do I still need Kong (API Gateway)?” The answer lies in the fundamental difference between North-South and East-West traffic. ...

Answer-first: Complete architectural blueprint of a Go 21-service e-commerce platform. Covers domain boundaries, traffic flow, and event-driven patterns. When transitioning from a monolithic platform to a distributed microservice setup, the hardest question isn’t “How do we write the code?” — it’s “How do these moving parts talk to each other safely, and why is each boundary drawn exactly where it is?” This post is the architectural anchor for the full composable commerce series. It presents the complete system blueprint and explains the reasoning behind each domain boundary. For deep-dives into specific layers, each section links to the dedicated post in the series. ...