don't just accept this as normal and burn yourself out hoping things improve - that's how people end up miserable and resentful. also don't go venting to coworkers about it first or making a big emotional scene; you need to approach this strategically.
the legal answer really does depend on where you live, but here's the practical thing most people skip: document everything. start keeping a simple log of when you stayed late, how long, and what you actually worked on. not obsessively, just a few quick notes each time. this matters because even in places where salaried exempt employees aren't guaranteed overtime pay, there are still limits. some jurisdictions have minimum salary thresholds that disqualify you from being "exempt" in the first place - meaning your employer is breaking the law. and honestly, even if you're legally exempt, most companies have internal policies about reasonable hours that your manager's probably violating. having dates and times makes it way harder for anyone to brush you off later.
before escalating to HR or legal stuff, have a direct conversation with your manager about expectations and workload. not accusatory, just factual: "i've been staying late regularly for months, and i need clarity on whether this is temporary or permanent, and how it factors into my role." sometimes managers don't realize they're creating an unsustainable situation. if nothing changes after that, then look up your specific country/state labor laws and check if you're actually classified correctly. contact your labor department's hotline if you're in the US - they answer these questions free. if laws are being violated, you've got documentation and you know what your options are.