[MrSaints]

> The functions take about 10s-15s to execute on cold start

This may be a bit of an exaggeration, and may vary depending on your deployment (from experience, it takes up to 5s at most), but I agree. There is a very noticeable cold start time which makes it not ideal for any business critical services. It is probably only good for things like document conversions.

[kevincox]

This is also something that you can optimize down to a small number of seconds. Crazy things such as bundling+minifying nodejs apps can make a difference. However that may make debugging difficult.

There is some latency in the infrastructure but I have found that most of the delay is puling the image and actually starting the app. So small images with few layers and fast boot up will help a ton.