Serverless vs. Edge: Where Should Your Backend Live?

As the line between frontend and backend blurs, deciding where your compute actually runs is critical for latency and performance.

• Traditional serverless functions (like AWS Lambda) typically run in a single, centralized region. This is great for heavy database processing but can introduce cold starts and latency for users far from that data center.
• Edge computing pushes those serverless functions to Content Delivery Network (CDN) nodes globally. Your logic executes mere milliseconds away from the user, making it ideal for authentication checks, localized data fetching, and A/B testing.
• When building modern decoupled architectures, I prefer routing heavy database mutations to traditional serverless endpoints while keeping middleware and auth logic strictly on the Edge.