Hello,
I would like to ask you where can I find information about the maximum current draw from GPIO pins. I just wasn’t able to find it anywhere in the datasheet.
Thank you in advance 
Hello,
Maximum current depends on pin configuration, 1 mA in standard output and 8 mA in high-drive output. You can configure the output type in software. If I recall correctly the total current of all pins can be 25 mA at once.
nRF52 data sheet has exact specification.