Cada página abaixo é uma pergunta que cai em processo internacional, com a resposta do jeito que eu treinei: em inglês, estruturada, com a pegadinha clássica marcada quando existe. É o mesmo material que vira flashcard e simulado dentro do app, aqui aberto.
JavaScript · 13 perguntas
What is a Closure?2 minWhat is the difference between const, let and var?2 minWhat are the types of Functions in JavaScript?2 minWhat is `this`?2 minWhat is bind, call, apply?2 minWhat is Hoisting?2 minWhat are Classes?2 minWhat is a Prototype?2 minTruthy and Falsy?2 minDifferences between Promises and callbacks? Why do we prefer Promises?2 minWhat are the differences between Promise combinators?2 minWhat happens when you await a non-Promise value?2 minHow do you handle errors in async/await code?2 min
TypeScript · 9 perguntas
What is TypeScript?2 minWhy is TypeScript good?2 minPartial, Required, Pick, Omit, Record — when would you use each?2 minDifference between interface and type?2 minCan you explain generics?2 minDifference between unknown and any?2 minWhat is a type guard?2 minWhat is a discriminated union?2 minWhat is `never`?2 min
Node.js · 11 perguntas
What is Node.js?2 minThe Event Loop2 minWhy is Node.js non-blocking?2 minWhat is the difference between process.nextTick(), setImmediate(), and setTimeout(fn, 0)?2 minWhat are Node.js streams?2 minWhat is backpressure?2 minHow would you detect and fix a memory leak in production?2 minWhen does the Garbage Collector run?2 minHow do you handle errors globally in Node?2 minNode.js is single-threaded — how do you use multiple cores?2 minCommonJS vs ES Modules?2 min
NestJS · 6 perguntas
React · 11 perguntas
What is React?2 minWhat is the Virtual DOM?2 minComponent vs Element?2 minProps and State?2 minHow can a child talk to its parent?2 minWhat is a Hook?2 minWhy do list items need a key?2 minuseEffect traps (cleanup + dependency array)2 minWhat is the Context API?2 minWhat is React Router?2 minRedux vs Context?2 min
Testing · 2 perguntas
SQL / PostgreSQL · 7 perguntas
REST / HTTP · 7 perguntas
GraphQL · 5 perguntas
Real-Time · 3 perguntas
SOLID & Design Patterns · 8 perguntas
AI / LLM Engineering · 23 perguntas
What is a token? What is a context window?2 minWhat is RAG?2 minRAG vs Fine-tuning vs Prompt Engineering?2 minHow do you choose a model?2 minThe RAG pipeline (memorize this flow)2 minWhat is chunking?2 minWhat are embeddings?2 minWhat is a vector database?2 minWhat is hybrid search and re-ranking?2 minWhat are LLM evals? (THE 2026 differentiator)2 minWhat causes hallucination? How do you reduce it?2 minWhat are guardrails?2 minWhat is LLM observability?2 minHow do you optimize LLM cost and latency?2 minWhat is structured output?2 minTemperature?2 minWhat is tool/function calling?2 minWhat is an AI agent?2 minAgent design essentials2 minWhat is MCP?2 minWhat is conversation memory?2 minMultimodal basics (voice and images — your Focca-AI does both)2 minWhat is Thompson Sampling? (it's on your resume — they WILL ask)2 min
System Design · 17 perguntas
The framework (ALWAYS follow this order, out loud)2 minLatency vs throughput?2 minWhat is RPS? (the back-of-envelope math)2 minWhat are p50 / p95 / p99?2 minNumbers to have in your head2 minLoad balancer vs API gateway?2 minHow do you scale reads?2 minHow do you scale writes?2 minSQL vs NoSQL in a design round?2 minCAP theorem?2 minQueue vs Pub/Sub?2 minRate limiting?2 minMicroservices vs monolith?2 minObservability?2 minResilience patterns (drop these terms naturally)2 minClassic problems to practice out loud2 minAI SYSTEM DESIGN (expect at least one)2 min