I feel like Flask can be ok if your application is simple enough that you can process each request independent of all other requests. If your requirements are

I feel like Flask can be ok if your application is simple enough that you can process each request independent of all other requests. If your requirements are more involved than that, Flask is an obstacle. The way it gives each request its own context makes it hard to have any kind of communication between them, without some kind of "spawn a gevent to wait for a signal" hackery. Also, Flask comes with Jinja but they should totally be separate. Why should a network protocol layer come with a frontend templating system?