Google levels affect interview expectations.
L3 (Entry-level): No system design. Lower complexity expectations. More hints allowed. Focus on fundamentals.
L4 (Mid-level): System design added. Solve medium-hard with minimal hints. Discuss trade-offs proactively.
L5 (Senior): Complex system design. Solve hard problems independently. Lead discussions. Show breadth and depth.
Level determination: Recruiter proposes based on resume. Can adjust based on performance. Down-leveling is possible. Up-leveling is rare. If borderline, aim for the higher level.