Ask HN: What helps you focus at work?

I have been having a problem for the last 6 months or so. I'm working as a software engineer and at my regular job I can't seem to focus more than a few minutes at a time. This has been getting worse as of late. This is not an issue with programming in general since when I'm working on side projects in the afternoon I find that I can't stop working until I'm tired/have to got to bed. The weird thing is that I'm working with Python both on my day job and on my side projects, it's just that it's something with my day job that I can't seem to find the motivation to keep going. Obviously I can't quit, to work on my side projects now full time (though I would like to progressively/eventually do it). I would like to ask how have you dealt with similar problems before?