Interview practice by topic

Structured interview questions across programming, databases, systems, and problem-solving. Choose a topic to begin.

Java

Core language, OOP, collections, concurrency, JVM internals.

Single Responsibility, Open/Closed, Liskov, Interface Segregation, Dependency Inversion.

Gang of Four patterns, creational, structural, behavioral, with explained Java code.

Monolith, client-server, layered, microservices, SOA, event-driven, serverless, with diagrams.

The Git model, everyday commands, branching, undoing mistakes, remotes, team workflow.

Classic interview brain teasers: two ropes, liars and doors, water jugs, weighing, Monty Hall.

== vs ===, let/const, closures, hoisting, 'this', prototypes, event loop, promises, DOM, performance, TypeScript.

Virtual DOM, JSX, components, state & props, re-rendering, hooks, custom hooks, Context vs Redux.

The event loop, non-blocking I/O, modules, streams, clustering & worker threads, npm.

Data types, mutability, type conversion, variables and scope, truthiness, numeric literals.

Relational modelling, ER diagrams, normalization, transactions, indexing, NoSQL.

Querying, joins & subqueries, schema changes, views, indexes, performance, query patterns.

Big-O, arrays and strings, sorting, searching, hashing, linked lists, stacks, trees.

HTTP, REST, DNS, TCP/IP, HTTPS and TLS, hashing vs encryption, XSS/CSRF, sessions, JWT, OAuth.

Cloud models, Docker & containers, Kubernetes, CI/CD, environments, deploy strategies, observability.

The HR round: tell me about yourself, why this company, strengths, STAR stories, salary, questions to ask.