Absolutely. Saving 30% on a cloud bill is not a super high priority for new companies. Staying frugal is important, but I find this mostly applies to unnecessary expenses, not necessary but slightly more costly expenses.

Don’t get the 27” inch iMac, get a second hand office chair. This will free up enough cash so you can take the more expensive but quicker hosting / infra options like Heroku and Lambda.

One of the things with Lambda etc is that while they are cost-effective (and flexible) when a business starts, they also can also lead to lock-in (not just with the serverless functions themselves, but queueing services etc). A few years down the track, a business may find themselves spending quite a lot of money with Amazon, and being unable to move away without a major re-engineering effort.

Then again if you're aiming at high growth, you'll be looking at some degree of re-architecting at least every few years anyway to cope with the 10x system problem.

If using FaaS can be a quick bandaid solution to get you up and running without worrying about having to design your own equivalent of the fail whale, then a certain degree of lock-in might be worth paying.

A couple of years down the road, however, will give you both personnel and money to handle a re-architecture.

FAAS (Or, MSA) adds a ton of complexity right off the bat. Why take on that risk when you have little money and less time?

Well, at least you have a business. I find vendor lock in to be about the lowest priority on my list. Also, the lock in is pretty exaggerated. Just make sure to keep business logic separate from the cloud plumbing, as per the OP example.

It's not just about separating business logic from "cloud plumbing". It's building you infrastructure around services that cannot simply be replaced elsewhere, or cannot be replaced easily - if you want to move from AWS Kinesis to (say) Kafka for message broking, or from DynamoDB to Postgres.

There is a reason Amazon gives away a lot of free credits to startups, and it's the same reason drug dealers give away free samples. If the economics are right, and growth is strong then you might be okay - but you also don't want to find yourself with a $100k/month AWS bill in a startup with only $2m of annual revenue.

(P.S Greetings from the other side of the Spree. I love La Lucha on your street!)

The useful thing is that in the case of at least Azure Functions, their back-end is open source. There's plenty of open source alternatives, so you can migrate to a bare metal hosted alternative if it brings down costs and maintains the same level of scalability. This also emphasizes the need for cloud agnostic frameworks.

Every startup wants to reach the point where vendor lock-in is an issue. IMO, it's a useless boogeyman. If vendor lock-in lets the start up move faster, find the business, and make it 2-3 years down the road, they should pick vendor lock-in every single time.

When that time comes, hopefully you have found product market fit and are capitalized well enough to make the move - see Dropbox.