Eh, I'm sure there are many things Jenkins is OK at, but it's not that great of build server.
The Multi-Configuration Project abstraction (IE build matrices) is clunky and the plugin ecosystem doesn't respect it well (eg. the Gerrit plugin is extremely popular but very brittle here). So you wind up with O(n) projects anyway and still needing to copy and paste configuration among them.
Also Jenkins configuration itself is pretty nuts - settings splattered all over the web UI, backed by XML - compared to the simplicity of modern tools like Travis (which uses YAML).
And Jenkins' UI I would definitely categorize as typically-poor open source UI, having evolved and grown more complex over many years with no strong guiding vision.
The Multi-Configuration Project abstraction (IE build matrices) is clunky and the plugin ecosystem doesn't respect it well (eg. the Gerrit plugin is extremely popular but very brittle here). So you wind up with O(n) projects anyway and still needing to copy and paste configuration among them.
Also Jenkins configuration itself is pretty nuts - settings splattered all over the web UI, backed by XML - compared to the simplicity of modern tools like Travis (which uses YAML).
And Jenkins' UI I would definitely categorize as typically-poor open source UI, having evolved and grown more complex over many years with no strong guiding vision.