Right, you can't do calorie deficit forever. At some point you get to where you want to be and then shoot for calorie equilibrium. I suppose another way is to do calorie deficit during the week, then allow yourself cheat days during the weekend. But bodies generally like it better if you're consistent all week.
A big problem people have is when they try to lose too much weight too quickly, like, say, 30 pounds in eight weeks. That's insane, and it's really hard to get there by calorie reduction alone because you'd have to cut your daily calorie intake by something like 2,000 calories a day to achieve that, and 2,000 calories is closing in to the recommended daily total calorie intake for grown men. The other part is people who lose too much weight too fast tend to boomerang and gain it all back just as quickly due to psychological reasons.
The most reliable way to lose weight and keep it off is to shoot for losing one pound per week. Wanna lose 25 pounds? Budget six months for that. That would require reducing calorie by 500 per day from whatever your recommended limit is, so, probably eating 1,800 or 2,000 calories in a day. It's not super easy because you'll probably have to give up snacking, but it's doable, and you don't end starving yourself in the process. Slow and steady wins that race every time.