Creating and deploying API servers is a space with a lot of options and many different ways to achieve the same end-result in both development and operations. In this post, I’m going to describe my experience with debugging intermittent HTTP 502 responses from NodeJS Express servers fronted by an AWS Application Load Balancer (ALB), and present the solution to solve these intermittent 502 errors. If you’re already familiar with Express and AWS ALB, you can skip to The 502 Problem
