For the last two years, DH has primarily been a SAHD after he left his administrative role in higher education. It was a decision based on a combination of factors including supporting me while I finished my Master's, my own work travel schedule increasing, and dissatisfaction in his previous role. He's worked freelance/part-time since then and we've added baby #2 to our family (currently 7 mo old).

He's casually been looking at returning full-time and submitted a couple applications this weekend. Well - one of them has already led to a phone interview tomorrow!

I don't want to get ahead of ourselves since there is so much of the process left to go, but I'm excited for him! Plus, we really need the additional income to make some progress towards some debt we are carrying after starting private school for LO1 last year and new baby/maternity leave expenses. So I am crossing my fingers hard for him/us.

As we prepare for this possible change, I wanted to see if any other Bees out there had been through something similar and had any advice.
I know we will need to use some of his additional income to cover increased costs like gas (for him to get to/from work and more daycare travel days). As well as increased childcare costs (aftercare for LO1 at school, moving LO2 from part-time to full-time). And I figured adding some conveniences to our budget will keep us sane (cleaning service, lawn service).
What else did you do to make this transition?
How did your kid/s handle a longer day at school/care if they were used to one parent being SAH?