There's a few reasons why this scenario wouldn't be a good fit for cloud functions, but that "couple of seconds start-up time" can be almost entirely removed from the equation by keeping the Django instance alive (all cloud function type offerings will have a concept of cold and warm starts, and some way to control persistence across calls on the same "instance").

I've run Django on AWS Lambda in a a scenario that scaled between 25-250 calls per second depending on time of day (for a runtime of 5-30 sec). Moving Django's bootstrapping so it would stay warm across calls was very easy.

Silly question, but under nginx or apache do django instances persist or are they recreated for every new request?

Not if you do it right.

a) you get to fire the devops person, which saves $150k+ a year.

b) you add appropriate caching layers in front of everything.

c) you spend time adding features, which generate revenue.

I've done all of this before at scale. This whole case study was written about work I did [1]. Two devs, 3 months to release, first year was $80m gross revenue on $500/month cloud bills. Infinite scalability, zero devops.

[1] https://cloud.google.com/customers/gearlaunch