Can you elaborate on what your application does, what’s a basic flow of a request, and finally, what are the high-level steps you take to ship a new feature or API endpoint?
Basically we have an API that performs asynchronous data analysis and processing. Our fronting service receives a request, writes some metadata, and places the request in a "queue", which is picked up by a backend poller that starts a workflow execution, which orchestrates the fulfillment of the request. This is all serverless (AWS tech...API Gateway, Lambda, Step Functions, S3, DynamoDB, CloudFormation, CloudWatch, etc.). Serverless makes deployments much easier, since we can version our Lambdas and State Machines using CloudFormation, and have many different versions running at the same time (not fun if you're managing your own hardware!). We have a CD pipeline that builds code changes, deploys them to a test account, and runs integration tests. We use CloudWatch Alarms to monitor production and alert us of any issues.
We have some development scripts for pushing code changes with CloudFormation for testing during development. We use that to develop, then once we check the code in, it works its way through our pipeline and into production.