I personally run ConTeXt as a service (as a sort of do-it-yourself Overleaf).

I use floobits (https://floobits.com/Denubis) as an intermediary code server, and their floomatic sevice(https://floobits.com/help/floomatic) running  on a server I have. That then calls a shell script that invokes ConTeXt, which writes logs and pdfs to an nginx monitored folder. It's been running for about 4 years now and has been solid enough for me to use without thinking too much about. 

Happy to share code and details. My deployment is super-hacky, but it works?

-Brian