What I did is go to sleep when the toddler does and then wake up at four and do coding work till toddler woke up. Then keep naps going for as long as possible.

What I did is go to sleep when the toddler does and then wake up at four and do coding work till toddler woke up. Then keep naps going for as long as possible. Work a bit (email/communication) in the evening to be prepped to be productive at four. (And mind you, I'm not an early waker, but desperation breeds solutions). Also, can the first grader give you blocks of time when they are in charge of the toddler? My younger kids worshipped the elders at that age.