Salarymallory different variations worked at different life stages.
After ds1 was born and and I went to 3 full days that worked well in terms of childcare and 2 weekdays with him.
My parents did 2 days (travelling to us and staying) and after a while they moved much nearer and I went to the 1 full day (when he was in childcare) and 3 part days, so my mum had him for the sane amount of time but spread over 3 instead of 2 days.
I dropped to 3 x 6hr days after I had ds2, by then ds1 was in pre-school.
I think when I went to 4 x 5hrs ds2 was at preschool.
I increased to 4 x 6hrs at some point when they were both okay to get themselves home from school and be home along for half hour or so. So ds2 would have been yr 4.
I've stuck at that since (bar some short time working following a traumatic life event).
As I said I'm basically full time for a few months over the winter, but taken that time back over the year. I have been paid out the extra hours when they built up one year.
I used a mixture of childminder and my mum. I'd drop off childminder and she'd drop at school/preschool, my mum would collect from preschool and I'd be home for school pickup etc. This worked really well as childminder was flexible for mixing days if my mum was away / ill and my mum would cover childminder holidays. They don't need childcare anymore, and barely seem to notice if I'm home or not.
I'm no longer doing it for childcare but because it suits me, and I can afford it.
I'm an accountant in a regional practice, when I first went part time my workload was reduced (someone else had been managing it while I was on maternity leave so they kept some on my return). I've progressed as much as I want to (don't want a partnership) and am respected by my bosses, peers and juniors.
I've been in the same job throughout (21 years now) and they have been very flexible throughout, mostly because I am good at my job and they want to to keep me, and also I think because I am also flexible in return - although probably a lot more so now the kids are older than in their way years.