I built Dependabot ( https://dependabot.com ), a service that checks your dependencies are up-to-date every morning and creates pull requests for you if they're not. Intention was to make dependency management suck less, whilst also adding a bit of runway to a bigger startup I wanted to do. * Spent 2 months building it - much longer than I'd thought. The work required to get from a prototype (2 days) to a SaaS produc…
That's pretty cool, I have been thinking of building something similar, but for Python. How hard is it to add new languages? What is the tech stack? Does it cost much to keep it running?
Adding new languages is as easy as the package manager makes it... which is normally still quite hard! The core logic for Dependabot is open-source here, including all the language-specific logic for Ruby, JS and PHP, and a starter (lots of work still required) for Python: https://github.com/gocardless/bump-core.
For the app itself, we used Ruby (because we'd built the original core gem, which was https://github.com/gocardless/bump, in Ruby at a work hackathon years ago).
Costs under £50 a month to keep running at the moment, creating about 2,000 PRs a month. We could really do with getting it into the GitHub marketplace so we can start charging people and cover those costs!