Let’s first talk about what’s common between them
Both facilitate communication between apps/services
Both manage traffic
Both help with service discovery
Both enable better observability of the system
What’s different
An API gateway operates at the application layer (high level)
A service mesh operates at the infrastructure layer (low level)
An API gateway focuses on business logic
A service mesh focuses on service-to-service communication
An API stands between external & internal apps
A service mesh stands between internal services
An API gateway enables transformation of requests & responses
A service mesh simply relays communication as is
An API gateway can work with monolithic & micro service applications
A service mesh is means for microservice applications only
API gateway is a more established technology
Service mesh is a new and nascent technology
There are many vendors for API gateways
Service mesh is mostly open source
API gateway is easier to get started with
Service mesh involves a learning curve
Examples of API gateways: Apigee, AWS API Gateway, Mulesoft, Kong, Tyk
Examples of service mesh: Istio, Linkerd, Kuma, Consul
