What are some of the challenges you've faced in going that route, and why did you decide to build on Lambda (or equivalents)?
The main challenges that we've had are pretty funny tbh. The documentation is scattered because we use the Serverless framework and when you are looking for answers people maybe using the wrong terminology. The ecosystem isn't set up well for transpiring ES6+ features, and we were waiting for a while for queues as an event source (all good now!). when you do have to interact directly with amazon the documentation is terrible.
the only other thing that is funny is having to explain the benefits to other people, and how it works. Devs that are deep in the standard monolithic framework approach seem to take a little longer on the uptake, but thats not really a big deal.
Keep an eye out for our open source Heroku built on GCP