Winning with JavaScript in Serverless Apps

JavaScript now powers an enormous portion of the serverless world, but writing efficient functions requires more than just knowing the language. This session explores the JavaScript-specific nuances that determine performance, scalability, and cost across serverless platforms. Rather than focusing on providers, we’ll examine how different serverless execution models (isolates, containers, micro-VMs, and edge runtimes) influence JavaScript behavior. Examples include: - Isolate-based runtimes (Cloudflare Workers, Deno Deploy) and how they favor smaller bundles and near-instant startup - Micro-VM or container-based runtimes (AWS Lambda, Azure Functions, GCP Cloud Functions) where dependency size, I/O strategy, and initialization code matter much more - Edge vs. centralized execution, and how JavaScript’s non-blocking model fits into ultra-low-latency workloads This session includes some code snippet walkthroughs and horror stories of serverless failures. I have seen in my career and some of the gotchas that everyone misses in these hostile environments. Attendees will leave with a deep understanding of how to write JavaScript that thrives in serverless environments, how runtime architecture changes, what “efficient” means, and how to choose the right serverless model (edge, container, isolate) for the job based on JavaScript’s strengths and constraints.