I have done much the same in plain old Java, at a couple of jobs, going back ten years or so.
No OTP, GenServer, etc. Just a webserver and some framework for scheduled jobs, third party or write your own. Config enables individual routes and jobs at the top level. You can deploy one instance with everything enabled, or a hundred instances with the customer-facing web routes enabled in 60, API routes in 20, admin routes in 5, report generation jobs in 10, maintenance jobs in 5, or anywhere in between.
The only discipline you have to stick to is that you must pass information between components in a way which will work when the app is distributed. A shared database is the most obvious, and may be enough. We also used message queues, and at one point one of those distributed caches that were all the rage (Hazelcast / Terracotta / Infinispan / EHCache / etc - anyone remember JavaSpaces and Jini?).
No OTP, GenServer, etc. Just a webserver and some framework for scheduled jobs, third party or write your own. Config enables individual routes and jobs at the top level. You can deploy one instance with everything enabled, or a hundred instances with the customer-facing web routes enabled in 60, API routes in 20, admin routes in 5, report generation jobs in 10, maintenance jobs in 5, or anywhere in between.
The only discipline you have to stick to is that you must pass information between components in a way which will work when the app is distributed. A shared database is the most obvious, and may be enough. We also used message queues, and at one point one of those distributed caches that were all the rage (Hazelcast / Terracotta / Infinispan / EHCache / etc - anyone remember JavaSpaces and Jini?).