Browse and take tests to sharpen your skills
Advanced integration scenarios between a NestJS API and a React client: BFF boundaries, cookie-based auth, CORS with credentials, DTO validation, and structured error mapping for forms and global UI.
Compose networking, Alembic/Django migrations, SQLAlchemy pools, secrets, volumes, and everyday incidents when a Python service talks to Postgres in containers.
Cluster hashing, Streams, replication, memory policies, and production reliability. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Hashes, sorted sets, pipelines, Pub/Sub, transactions, and cache patterns. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Foundations: data types, basic commands, TTL, and key naming. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Advanced concurrency, context, generics, profiling, and production HTTP patterns. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Concurrency, interfaces, methods, JSON, HTTP basics, and practical error wrapping. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Foundations: packages, types, zero values, slices, maps, and basic error handling. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.
Concurrency (`synchronized`, `volatile`, locks), `CompletableFuture`, JVM memory model basics, records/sealed types, advanced Streams, and common performance pitfalls. Mix of single-answer and multiple-answer items.
Interfaces and abstract classes, generics, collections/`HashMap`, exceptions and try-with-resources, `Optional`, Streams basics, and equals/hashCode contracts. Mix of single-answer and multiple-answer items.
Java foundations: primitives vs references, classes and methods, String immutability, arrays/lists, control flow, and the JVM entry point. Mix of single-answer and multiple-answer items.
Practical development: modules and events, queries, registers, transactions, extensions, jobs, and integration surfaces. Mix of single-answer and multiple-answer items; multi-select questions ask you to select every correct statement.