Ask HN: Has anyone successfully opposed a patent before?

In https://patents.stackexchange.com/ and Quora, I can find discussion on how to oppose a patent by submitting prior art but would like to know if anyone can share their experience in opposing a patent. A walk through of the whole process will definitely help a lot.

Here is the background on the code generation patent that should not be granted in my opinion as there are open-source projects doing the same thing a while back:

https://twitter.com/fehguy/status/900736518884425728