For CI/CD you can get quite a long way with git hooks and for code review I would look into git appraise. that's the best one I've found but I would really like to hear if someone else has a better idea here!
"So, git hooks are basically executable scripts (of whatever language you have available, I use bash) placed in the .git/hooks dir, whcih are then executed at whichever event is designated (by the name of the script itself) For me, it's post-recieve. After initial setup, a push automatically triggers the post-recieve hook that does something like the following from my git dir:
GIT_WORK_TREE=..../example.com git checkout -f
Learned from a few sources (shout out to Dreamhost for my original intro to this idea), but here are some relevant readings:
https://www.ibm.com/developerworks/library/wa-git/
https://opensource.com/life/16/8/how-construct-your-own-git-... "
It's pretty easy to trigger ci runs via git hooks, and once you're used to it, checking their results in jenkins instead of in the git repository UI makes no difference. But code reviews really need a dedicated interface.