With any work ask about external factors, not deadlines. No company operates in vacuum and there’s almost always an external factor. It may be well-defined and

With any work ask about external factors, not deadlines. No company operates in vacuum and there’s almost always an external factor. It may be well-defined and clearly dated (a scheduled event or launch in which your work plays part). There could be an external factor not explicitly connected to your work, even though it should be (you could help make that connection). No external factor whatsoever concerning your work is also informative: it could mean there’s not enough mutual trust, or your customer is investing into pure R&D, or it’s very low-priority, there’s a disagreement within the company, etc. It’s not the same as asking about deadlines, but the question should definitely be asked (and situation monitored for changes)—proposing a schedule/“deadlines” without awareness about external factors sounds like a bad idea. Some customers may be inclined to manage more and set specific deadlines rather than get into the external factors discussion. This spares you from some higher-level planning but doesn’t fundamentally change the ultimate responsibility of managing expectations (aiming to under-promise) regarding work scope and timeframe: fixed scope means variable timeframe, fixed timeframe only means you adjust the scope part of the equation. If expectations are unrealistic and there’s no flexibility in either direction, run.