[siquick]

Yes I'm sure it's down to the cold start issue of Lambda. Are there any tips on how to keep it warm?

I didn't go down the static route as I have tens of thousands of product pages. Will check out the Incremental Static Generation - thanks.

[carmen_sandiego]

So yeah in that case I would do Incremental Static Regeneration but don’t pass all your product paths at build time. Instead you can use the fallback mechanism to render individual product pages on request, but then serve the result statically thereafter. That way you don’t build tons of pages at build time that people may not view anyway, but the pages that do get views will stay fresh and fast.

If you were using your own Lambda you could set a minimum reserved concurrency to avoid cold starts, but I don’t think Vercel gives you that level of control. The main thing to do is try to serve as much statically as possible so that it reads straight from the CDN cache or static file store and that way it never hits your Lambda on requests.

With ISR the Lambda updates the rendered file in the background, rather than in response to a request (generally), and the user is just served the last generated render. So in that scenario the Lambda latency is taken out of the equation.

If you know which products are most important you could also render a subset of them at build time and let the fallback handle the long tail ones.

[siquick]

Great, thank you!