Gateway vs Mesh vs Load Balancer vs Ingress

Overlapping tools, different jobs

A load balancer spreads connections across servers (layer 4 or 7) and is the simplest building block. A reverse proxy (nginx, HAProxy, Envoy) forwards requests and is the engine inside many other products. An API gateway adds API-specific policy (keys, quotas, transformation, developer portal, analytics) on top. In Kubernetes, an Ingress resource describes HTTP routing from outside to services and needs an ingress controller to implement it; the newer Gateway API (Gateway, HTTPRoute) is a more expressive, role-oriented successor that many gateways and meshes support. A service mesh is about service-to-service traffic and can also provide an ingress gateway. Real systems often combine: cloud load balancer → API gateway → mesh.

Where each one sits

Use the table to decide which layer owns a given requirement.

Component          Scope               Typical jobs
Load balancer      L4/L7, any traffic  spread load, health checks, TLS passthrough
Reverse proxy      L7                  routing, caching, compression (nginx, HAProxy, Envoy)
API gateway        north-south         auth, quotas, rate limits, transformation, analytics
Ingress / Gateway API (K8s)  cluster edge  declarative routes into the cluster
Service mesh       east-west           mTLS, retries, circuit breaking, telemetry between services

Quick check: Which is mainly about service-to-service traffic inside a cluster?

• CDN
• Service mesh
• DNS registrar
• Email gateway