Game servers are a great example. What's interesting is how many different kinds of apps need game-server like infrastructure: https://www.figma.com/blog/how-figmas-multiplayer-technology...

We've been talking to a lot of startups doing communications tools, especially for remote work.

Lots of full stack apps benefit from app servers + redis cache in different regions. They need a database connection, but if they're already done the work to minimize DB round trips they might just work with no code changes.

There are also a bunch of folks doing really dynamic video and image delivery. Where an individual user gets an entirely unique blob of binary data.