Every developer knows the "happy path"—that glorious moment when your code works perfectly on a small sample size. But when the "happy path" meets the reality of 100,000+ emails and strict API rate limits, things tend to break. This is the story of how a bottleneck in my AI startup, Glim, led me to build and contribute the Step Functions construct to the SST (Serverless Stack) ecosystem. The Problem: The Gmail "Wall" I was building Glim , an AI assistant designed to help users manage their chaos-ridden inboxes. We offered real-time filtering and a powerful bulk-cleanup tool that could archive or delete thousands of emails based on specific criteria like sender, date, or domain. To make this work, I had to implement a full inbox sync . According to the Google API documentation, this is a two-step process: Fetch a list of all email IDs. Iterate through that list and perform a messages.get request for each individual email's full data.…