Node.js & JavaScript Backend¶

Runtime & Internals¶

• event loop and architecture - V8, libuv, event loop, clustering, where Node.js fits and doesn't
• v8 optimization - Hidden classes, monomorphic/polymorphic code, JIT, small function inlining
• closures and scope - Lexical scope, closures as heap data structures, module scope

Async Programming¶

• async patterns - Callbacks, Promises, async/await, thenable objects, AbortController
• streams - Readable/Writable/Transform/Duplex, backpressure, buffer optimization
• Concurrency Patterns - Actor model, CRDT, SharedWorker, binary protocols, deployment

Language & Type System¶

• modules and packages - CommonJS vs ESM, interop, package-lock, npm, module cache
• solid and grasp - SOLID/GRASP in JavaScript, algebraic types, immutable records, LSP
• Design Patterns (GoF) in JavaScript - Factory, Strategy, Observer, Adapter, Facade, Proxy, Flyweight, State

Architecture¶

• application architecture - DDD structure, layers, transport abstraction, context isolation
• data access patterns - Repository, Active Record, cursors, transactions, DAL
• dependency injection - DI vs module system, coupling reduction, platform abstraction
• middleware and http - HTTP/WS transport, middleware as Chain of Responsibility, multi-framework

Operations¶

• Error Handling - AppError, AggregateError, Error.cause, fail-fast, error types
• security and sandboxing - Crypto, password hashing, vm sandbox, macaroons vs JWT
• Performance Optimization - Round-trip reduction, Map vs Object, buffer optimization, DSL vs imperative