AWS API Gateway and Lambda

AWS API Gateway and Lambda is one of the most common serverless patterns in AWS because the gateway handles HTTP concerns and Lambda runs the business logic. For DevOps teams, it matters because it lets teams launch APIs quickly without maintaining application servers, load balancers, or patching host operating systems. Instead of relying on one fragile manual configuration, you can design a repeatable service boundary that stays stable while the workload behind it changes.

Core ideas

The main ideas to understand are proxy integration forwards most request details to Lambda in a standard event shape that is simple to start with; custom integrations and mappings offer more control when the Lambda contract should differ from the public API contract; Lambda authorizers can evaluate tokens or headers and return an IAM policy style decision for custom authentication flows; and simple CRUD APIs often use one function per route or a small set of functions organised by resource domain. These details shape architecture decisions, but they also shape day-to-day operations. When a team chooses defaults without understanding how the service behaves under failure, scale, or security review, the platform often becomes harder to debug than the application itself.

From an operations perspective, the goal is to keep the function contract stable and ensure the API surface, authorisation, and error responses are tested together. The comparison below highlights the choices that usually matter first. It is often better to start with a simpler design and add sophistication only after metrics, incidents, or delivery requirements prove the change is necessary.

Practical commands

aws lambda get-function --function-name orders-api-get
aws apigatewayv2 get-integrations --api-id a1b2c3d4
aws lambda invoke --function-name orders-api-get response.json

Practical CLI checks make the service easier to support in real environments. Use the commands below to inspect the current state and confirm that automation matches intent. Before you promote a change, verify event payload shape, error mapping, and authorizer cache behaviour before opening the API to real clients. A safe default is consistent response schemas and shared logging fields across all CRUD handlers. That discipline makes later troubleshooting, scaling, and security reviews far less painful.