I’ve been working 4d/week for the last 5 years as a Data Scientist. I first proposed it during salary negotiations with a small startup, who were surprised by it but were willing to give it a go. It worked out really well, and once I had that under my belt, I was able to ask for the same arrangement at subsequent job interviews - I would make a point to raise this up front, and it proved a good way to filter out companies that likely wouldn’t have been a good work/life fit. (I look after three young kids outside of work; wife is a corporate lawyer who has to work 24/7, so my 4d/wk schedule is important in maintaining some semblance of balance for the kids).

Now I’m at a multinational (a publicly listed health data company) and the arrangement continues to work well, even though I now manage a team of 8 data scientists. I’ve had colleagues who’ve dropped from 5 to 3d/wk, the company seems very flexible around this type of arrangement. At the startups I felt that I had to squeeze in 5d of work in 4d at times, whereas here the workload has felt more commensurate with the hours I have available (and my manager often checks in to make sure this is the case).

Overall I love having an extra day to the weekend (I take the kids out to places in London on Fridays when it’s considerably less busy). My colleagues with similar arrangements used this to split their working weeks in half, and that worked well for them.

Happy to answer any questions.