For a USAO position, you need a clerkship to be competitive. You’d ideally have recommendations/references, ideally from former AUSAs or USAs or judges. You should consider looking at multiple geographic areas. USAOs in big cities will get 400-1,000 resumes for a single opening and maybe interview 10 people. People move anywhere from 4 - 10 years after starting big law. It’s really hard to make a case for yourself if you don’t have trial or criminal law experience. Many offices have an unspoken policy of not hiring people the first time they apply. You have to apply multiple times to build credibility and demonstrate true interest in public service.

Hours will depend on the office. My sense is that the hours for a criminal division AUSA are similar to BigLaw in places like SDNY, EDNY, DNJ, CDCA, NDIL, NDCA, and other large markets. Probably a little better and fewer weekends. I’ve heard SEC lawyers have more work life balance.

People don’t “transition” from BigLaw to government enforcement jobs. These are highly coveted jobs that are extremely competitive.