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@AdarshChetan Dsa

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Ans: You’re still logged in because your authentication is stored or managed outside the app itself, either on the server, in system-level secure storage (like iOS Keychain or Android Keystore), or via SSO/OAuth providers. so when you reinstall, the app can restore your session.

Interview question: You deleted an app, reinstalled it, and you're still logged in. How?

Java tip: Use Optional to avoid null checks, but don’t overuse it in fields. Favor immutability, leverage records for DTOs, and keep methods small and focused. #JavaTips

Java tip: Prefer composition over inheritance, use Streams wisely (not everywhere), cache expensive calls, and always profile before optimizing. Clean code > clever code. #JavaTips

Advanced Java isn’t syntax—it’s JVM internals, concurrency GC tuning and smart architecture. Measure, profile, and choose trade-offs that scale in real systems.

Virtual Threads were step 1. Java 26 is step 2. With Structured Concurrency: You don’t just run millions of threads… You organize them. → Task groups → Shared lifecycle → Clear boundaries From messy async to clean parallel systems. Same power. More control. #Java #JVM