Digital Ocean hands out credits pretty often. I actually just got my first bill of the year this month after running my side project on free credits for months. Usually it's things like testing a new service or doing a survey. I'm not sure what it takes to get these credits, I've been a customer for nearly a decade but my average monthly spend is only like $20-$30.
MSDN Subscriptions still have them - but of course you’re still paying thousands of USD/year for the subscription and the credits you get included are a tiny fraction of that - and it’s not like it’s costing Microsoft anything to provide that either.
Microsoft has a solution they call Action Pack [1] where you pay ~$400/yr and get $100 in Azure credits each month. So basically $400 gets you $1200 worth of credits.
I'm not sure what the process is now, but previously it seemed if you were part of any accelerator, or raised money from a VC both AWS/GCP would give you 100k.