What we learned open sourcing a major part of Mailgun

One of the _good_ things about open sourcing parts of a larger stack of software is that it enforces protocols and API's in a much more thought-out manner.

I've also found that integration tests are a great thing here. If an internal application depends on certain behaviour, it's not likely that you'll have a test to begin with, but when the open source product conflicts with the internal, it's a perfect place to make integration tests to make both sides more stable.

I'm not a complete believer in all kinds of tests at all times, but I've found that the more extensive your tests are around things like this, the less breaks in the long run.

I'm impressed. Really. This should be a template for other companies to follow when opensourcing their stuff. While I don't use python Knowing that this lib is part of a service as heavily used as MailGun and that it's exactly the code you're using would give me a lot of confidence if I needed a tool like this.

The only thing not covered was that as a result of using a public codebase at the core of your app you've got to be extra careful in checking what's in each pull request... probably moreso than if they came from your employees.

Awesome!. As a, alibet very small, mailgun customer, I am happy to see them pushing a big chunk of their code open source.