Flutter

Tell us about your experience working with PostgreSQL and Redis

What are summarizingLong and LongSummaryStatistics?

gRPC — что это такое, работали ли с ним?

What types of exceptions exist in Java?

How will the algorithm change if using LinkedHashSet instead of HashMap + ArrayList?

public class Singleton { private static final Singleton instance; public Singleton() { } public Singleton getInstance() { if (instance != null) { synchronized (instance) { if (instance == null) { instance = new Singleton(); } } } return instance; } }

How does LinkedHashMap differ from HashMap? What ensures the insertion order?

How is HashMap structured internally? What is a bucket, how does insertion occur, what is a collision, and what is rehashing?

What collections did you use in your solution (HashMap and ArrayList) and what role does each play?