It's a Rails app that's hosted on Heroku. It's a simple CRUD app that's backed by a Postgres database, only a few lines of JavaScript. I am a data engineer and don't have the time to keep up with the constantly evolving Rails ecosystem. I don't need a web framework that makes breaking changes to add new features.
* I know Python, but guess that Django is a constant maintenance effort after looking at all the releases
* I also know Scala, but find it really difficult to maintain, as I noted in this thread: https://news.ycombinator.com/item?id=26539508
* I'm working on a Node / React app right now and it seems it will also require constant maintenance
I'm leaning towards Go. From what I understand, Go really cares about backwards compatibility and lets you build a CRUD app that'll continue to work with minimal maintenance. Interested in thoughts on the best technology for this.
I might encourage you to look at ASP.NET if you really want minimal maintenance and a modern-ish experience.
What's the CRUD aspect? If it's just the user login + progress saving, you could probably outsource auth and then store their progress as user-specific metadata, tied to individual question IDs. Doesn't seem like you need much of a backend at all. Maybe a cloud KV store at most (Cloudflare, etc.) or the free plan of some headless CMS.
If you really prefer a relational backend, services like ElephantSQL and Cloudflare D1 and DigitalOcean offer low-costed hosted Postgres that you don't have to maintain yourself (no updates, OS to manage). Instead of a full-blown backend, just write a serverless function that your frontend can talk to which will fetch from the database. But again it's easier (as in lower maintenace) to just use a preexisting solution or headless CMS.
Host your frontend anywhere, like Vercel or Netlify, since it's just static HTML + JS.
TLDR eliminate the backend parts that you don't need, and maintenance becomes a lot simpler. You don't need a backend stack or any other languages except HTML and JS.