Edge and Serverless: What You Gain and What You Give Up

Running code close to users sounds like a free speed boost. It can be, but it comes with trade-offs worth understanding before you move everything.

The upside

Lower latency for users far from your main region, automatic scaling, and no servers to patch. For content that can be cached or computed quickly, it is a great fit.

The catches

• Your database is often still in one region, so a fast edge function can spend its time waiting on a slow round trip.
• Runtimes are more limited, with restrictions on libraries, execution time, and memory.
• Cold starts and per-request pricing can surprise you at scale.
• Debugging distributed behavior is harder than debugging one process.

A sensible split

Put things like redirects, authentication checks, personalization, and caching at the edge. Keep data-heavy logic near your database.

Rule of thumb

Measure real user latency before and after. If the numbers do not improve, the added complexity is not paying for itself.