To be pissed at DP's long hours in new job

Depends how much he's earning.

Big pay bump and opportunity probably equals responsibility and he is in charge of something or someone and something will be reliant on him delivering.
he needs to get up to speed 9-5 will be doing (winging) the job, the rest of it in his own time is learning the job.
It takes time, cut him some slack
you sound a bit incompatible tbh

DH worked the UK and US shift for many years in his tech job. It meant we rarely had an evening together, but it allowed him to shoot up the ranks. So it was worth it - even though technically not contracted, it was what you needed to do to succeed in that organisation.

I would set a hard limit of no laptops during dinner or until the clear up has been finished.

I'd also try to book in one date night a week that you can have the whole evening together. When we started this it was really nice and appreciated.

Then I'd just support him. In the same way I would want to be supported if I was in a similar position.

Big caveat is with kids - he needs to be present for them and find more balance.

Sounds pretty normal to me. Well paid jobs are definitely not usually just 9-5pm.

I think you’re being a bit unreasonable here, as it’s a new and presumably highly paid job.

He obviously doesn’t want to let himself down, but he also needs to be careful that he doesn’t set a precedent as it could always be expected of him.

I haven't voted, as it is an "it depends" situation.

Some jobs do come with an expectation for being available.
Many jobs have an expectation that people will work 'to get the job done' rather than 'in set hours'.
Sometimes, when you are doing something new, it takes you a while to get on board with systems and language and procedures, and, if in a new job, I'd put the hours in to make sure I hit the ground running too.
Presumably there will be some training and induction to do and it is understandable he doesn't want to get behind with other things whilst doing those.

My dh is decades into his career, but now is a busy time for deadline, and he was working until about 11pm tonight. He doesn't do that throughout the year, but deadlines are deadlines.

So I'm leaning towards YABU. It sounds like he is enjoying it and full of enthusiasm.
It doesn't sound like an issue where he is ducking out of childcare responsibilities (I'm assuming you would have said), so I'd let him settle, then discuss it in a month or two once there is more of a regular pattern.

When I took a big promotion I had to do this just to get on top of the work and what I needed to know. It was such a jump it was like I was a brand new starter. It's really tough when everyone around you knows what they're doing and you're floundering. It was 3-6 months of that before I could revert to mostly normal hours. I think you're being unreasonable - in a long relationship there are times when you have to be the supportive one picking up the slack for a while, you're a lower priority for now but if he's usually a decent partner then that's just how it is for this period. If nothing has changed by summer that's time for a big talk.