When you get work assigned to you. Are you asked for how long it will take you to complete the work or does your manager give you a deadline to complete the work? Note: Manager was a senior developer but now a manager so he states he knows how long it might take and sets deadlines.

You should really take an opportunity to give yourself a bar rather than to follow someone else's, that's what I know.

@vintprox What do you mean by “give yourself a bar”?

@appmaker by "bar" I meant "deadline"

A task - I give estimate.

A project - there's a soft deadline, aka: optimistic management assumptions based on fuck knows what.
but for the tasks within, they are still mine to estimate.

But then I don't have a Senior Dev to fight with - I'm the Dev.

@C0D4 What if your manager (formerly a senior developer) says they know how long the task takes and wants you to do it in their stated timeline?

@appmaker they can have an opinion on what's a suitable time frame, something that's obviously going to take a couple of days vs a week or two is easy to identify, but it's still a rough idea, and sure they are entitled to question any excess time spent on a task, sometimes problems reveal themselves on the journey that wasn't accounted for, but actually being set fixed timelines has never been an issue from a "senior" in my career, mostly it's been management trying to push projects out way to early despite the evidence that something is going to take at best 6+ weeks and they want it in 1.

Maybe your manager knows stuff. Have a discussion if you disagree

Never. It takes as long as it takes and if he trusts the team he should be happy with that.