Most of the things I've added are for logging and orchestration. The most important unlock for us was the ability for us to enable chaining of Lambdas that work

Most of the things I've added are for logging and orchestration. The most important unlock for us was the ability for us to enable chaining of Lambdas that worked seamlessly with our orchestration. So Orchestrator kicks off 25 lambdas (A) that are reading files off S3. Each Lambda A reads 100 lines of that file and invokes a Lambda B to parse it. Lambda B parses and filters each line in its batch and sends it to Lambda C to be persisted or Lambda D if it needs to be discarded. We end up with hundreds or thousands of Lambda invocations and the orchestrator is aware of all of them. If there's a failure in any lambda, I can stop the entire job and retry from scratch. The orchestrator knows exactly when the job is done so I can easily chain it together with some other non-Lambda job in my system. Been working fine for us for ~200k invocations and 8k CPU minutes per day baseline with the ability to scale up to 10x that just by running more stuff. Our nightly job processes about 50gb of data in 3 min.