Vercel Serverless Functions (which use AWS Lambda) ...
When a lambda function starts for the first time, it’s a cold start.
Cold starts typically occur in under 1% of invocations.
The duration of a cold start varies from under 100 ms to over 1 second.
Vercel now also has experimental support for Edge Functions, which use a more constrained runtime than Node.js, enabling greater performance with near-zero cold starts.
We're improving site speed by caching expensive API requests. Let's close this issue and revisit only if performance fails to meet expectations after caching is in place.
Vercel has some docs around cold start claims:
Those docs suggest we may be able to nearly eliminate cold starts with Edge Functions: