I took about three years off to travel after ~12 months of working. It was very difficult to get back into the work force. Partially that was the economic environment. But probably the biggest issue was that I didn't really have the experience to be comfortably above entry level and for entry level roles companies preferred new grads.
That was a non-programming career though. For programmers that can pass a leet code style it's different. You probably could take a dump on a recruiter's desk and still get a job.
But, IMHO, it's wise to get 2-3 years of experience before taking significant time off. At that point you're solidly out of junior/entry level roles and into experienced hires.
I think <=1 year is common enough (at least in some world regions) for it to not be a problem, but much longer and people will start to ask questions, why you left, what you did and why you are coming back. Depending on the answers, it increases the risk of a miss-hire quite a bit especially for the first company that would provide a re-entry.
I can only imagine that taking longer can represent a greater challenge to re-entering the market. I assume some linear relationship between length of time and difficulty coming back.
That was a non-programming career though. For programmers that can pass a leet code style it's different. You probably could take a dump on a recruiter's desk and still get a job.
But, IMHO, it's wise to get 2-3 years of experience before taking significant time off. At that point you're solidly out of junior/entry level roles and into experienced hires.