Breaking Backwards Compatibility: The easy way

Say you have this piece of software that many people use. One day, you wake up and you have the urge to make them suffer. Well, there’s no better way to do so than breaking the software they’re using.

In this talk, I’ll walk you through very good ways to do so by showing examples taken from experience - because experience is the only thing that matters (TM) - so that you’ll be able, by the time this talk ends, to do the same to your users.

(P.S: If you’ve a kinder hearth, you can also do the exact opposite of what I’ll say and keep your users happy.)

Transcript

1. Breaking Backwards Compatibility
2. Breaking Backwards Compatibility Easy Way
4. For attending Still here feel free to interrupt @flaper87 flavio@redhat.com
5. Backwards Compatible... [...] If products designed for the new standard can receive, read, view or play older standards or formats, then the product is said to be backward-compatible[...] http://en.wikipedia.org/wiki/Backward_compatibility
6. Don’t use versioning
7. Don’t deprecate things
8. Inconsistency FTW
9. Assume you’re the user
10. Keep everything public
11. Keep users in the dark
12. On a more serious note
13. You’ve been that hacker
14. Why Does it matter? It’ll help you save TIME but not only that. It’ll also help you save MONEY and it does not end there. It also helps saving KITTENS.
15. Version Don’t re-invent it Cross-platform Cross-language Semver (?) Cap versions
16. communicate Let them know what’s going away Do that at least 1 cycle in advance Have a well defined release cycle
17. Consistent API Helps users migrating over new versions Helps you maintaining your software Design by contract
18. Privacy Rules Private by default Don’t expose internals, commons or utilities If it’s public, you can’t assume it’s not being used
19. Stability Attributes Stable shouldn’t break Unstable can break Be explicit about your software stability
20. Testiing Unit and functional tests are taken for granted Do integration tests If possible, run cross- version, integration tests
21. Questions?