Duration vs. Concurrency in AWS Lambda

I’ve been helping out on a project recently where we’re doing a number of integrations with third-party services. The integration platform is built on AWS Lambda and the Serverless framework.

Aside from the data hygiene questions that you might expect in an integration project like this, one of the first things we’ve run into is a fundamental constraint in productionizing Lambda-based systems. As of today, AWS Lambda has the following limits (among others):

  • max of 1000 concurrent executions per region (a soft limit that can be increased), and
  • max duration of 5 minutes for a single execution