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Everything you need to know about StackInterview and how to get the most out of your interview preparation.

What is StackInterview?

StackInterview is a free, structured interview preparation platform built for full-stack developers at every stage. It offers 1,000+ curated technical questions across JavaScript, React, Node.js, Next.js, TypeScript, MongoDB, SQL, and system design - along with explanations designed to build deep conceptual understanding, not surface memorisation. Whether you are preparing for your first developer role or a senior engineering position, the platform gives you the same structured, depth-first approach that real interviews demand.

What technologies are covered?

The platform currently covers: JavaScript (closures, prototype chains, event loop, async/await, ES2024 features), React (hooks, rendering behaviour, server components, performance optimisation), Node.js (event-driven architecture, streams, cluster, Express middleware), Next.js (App Router, SSR vs SSG, server actions, data fetching patterns), TypeScript (generics, type narrowing, decorators, strict configurations), MongoDB (schema design, aggregation, indexes, transactions), SQL (joins, window functions, indexing, query optimisation), and System Design (load balancing, caching, microservices, message queues, CAP theorem).

Are these real interview questions?

Yes. Every question in StackInterview's bank has been curated from real technical hiring rounds at companies including Google, Meta, Stripe, Airbnb, Atlassian, and many mid-to-large technology companies. Questions are reviewed by engineers who have conducted interviews at these organisations to ensure they reflect genuine hiring standards.

What are Company Interview Tracks?

Company Interview Tracks simulate the interview format of specific technology companies. Instead of browsing random questions, you follow a structured sequence that mirrors a real interview: multiple rounds, increasing difficulty, a mix of technical domains. It is the closest simulation of a real interview you can get without scheduling one.

What are Interview Guides and Articles?

Interview Guides are long-form editorial articles covering interview strategy, technology deep-dives, and preparation frameworks. They are designed to give you the conceptual context you need to not just answer questions but understand and articulate the reasoning behind your answers - which is what turns any developer, at any level, into a strong interview candidate.

Is StackInterview beginner friendly?

Yes - StackInterview is designed to work for developers at all experience levels. Questions start at a foundational level: variable scoping, basic hooks, simple SQL queries. They progressively move toward senior-level depth: event loop internals, server component rendering, distributed system design. If you are just starting out, you can use the platform to learn how these concepts work while also seeing what interviews look for - which shows you exactly what to build toward. You do not need years of experience to start.

How often are questions updated?

The question bank is updated continuously. We monitor changes in hiring patterns, technology updates, and community feedback to keep questions current. Major technology updates - such as React 19 features or Node.js v22 APIs - are incorporated as they become relevant to interview rounds.

Can I filter questions by technology or difficulty?

Yes. You can filter questions by technology track, difficulty level (junior / mid / senior), and question type (conceptual / code-based / architecture). You can also browse the full Question Library or use the Surprise Challenge feature for a randomised cross-technology sequence.

Is StackInterview free?

Yes, completely. StackInterview is free for all developers with no account required to access questions. We believe quality interview preparation should be accessible to everyone, regardless of whether they can afford expensive bootcamps or subscription platforms.

How is StackInterview different from LeetCode?

LeetCode focuses primarily on algorithmic problem-solving (data structures, dynamic programming, graph algorithms). StackInterview focuses on full-stack engineering knowledge - React architecture, Node.js internals, database design, and system design - which is equally important for senior engineering roles but largely absent from algorithmic platforms. The two platforms complement each other: use LeetCode for algorithmic prep and StackInterview for everything else.

Does StackInterview have a DSA / coding problems section?

Yes. StackInterview includes a full coding problems module with 215+ curated DSA problems - covering arrays, strings, two pointers, sliding window, binary search, trees, graphs, dynamic programming, and more. You can write and run code directly in the browser, test against real cases, and submit for a verdict. No external judge required.

How is the Problems section different from LeetCode?

StackInterview's Problems module is built for full-stack engineers preparing for FAANG-style technical rounds. Beyond just solving problems, it includes an AI Tutor for on-demand hints and approach breakdowns, a Weakness Radar that visualises your accuracy across DSA topics, and a Company Readiness score that tells you how prepared you are for specific company interview patterns - all generated from your own submission history.

Is the coding problems dashboard free?

Basic access - browsing problems, running code, submitting solutions, and using the AI Tutor - is free. The ML-powered dashboard (Weakness Radar, Company Readiness scores, personalised problem recommendations, and a 30-day study plan) is available to Pro subscribers.

What is Interview AI on StackInterview?

Interview AI is StackInterview's AI-powered mock interview feature. You practice by speaking your answers out loud - the AI listens, transcribes in real time, and scores every answer on three dimensions: communication, technical accuracy, and confidence. After the session you receive a full feedback report with an animated score ring, metric cards, model answers for comparison, and a per-question Q&A breakdown. All three interview types are covered: behavioral (STAR method), technical (DSA and system concepts), and system design (architecture, scalability, trade-offs).

How does an AI mock interview work?

The flow has four steps. First, configure your session: pick interview type, difficulty level, job title, and optionally enter a company name or paste a job description. Upload your resume for personalized, role-specific questions. Second, enter the interview room: the AI avatar greets you and asks questions verbally. Your spoken answers are transcribed live on screen so you can follow along. Third, get instant scored feedback: after each answer, the AI scores it on communication, technical accuracy, and confidence, and generates a model answer you can compare against. Fourth, review your full report: the session ends with an animated score ring, per-metric breakdown cards, pill-chip strengths and weaknesses, and a full Q&A accordion. Every session is automatically saved to your progress dashboard.

Is AI mock interview practice actually effective?

Yes. AI interview practice removes the biggest barriers to consistent preparation: availability, cost, and subjectivity. You can practice at any time without scheduling, receive objective scores instead of vague peer feedback, get instant model answers for comparison, and track measurable improvement across sessions. Studies show candidates who practice with structured AI feedback improve their performance by up to 35% compared to no preparation. The key is that StackInterview builds your skills - it does not give you answers during real interviews. Think of it as a driving school, not a GPS.

What is the StackInterview Resume Builder?

The Resume Builder is a free tool with no sign-up required. It includes 12 ATS-friendly resume templates built specifically for software engineers, a live preview as you edit, section-by-section content editing, and one-click PDF export. No account is required - open it, build your resume, download it. It is designed to complement interview preparation: build a strong resume, then practice answering every question it raises. You can access it at stackinterview.dev/resume-builder.

What are Interview Guides and Articles?

Interview Guides are long-form editorial articles covering interview strategy, technology deep-dives, and preparation frameworks. They go beyond surface-level answers to give you the conceptual context that turns preparation into genuine understanding - which is what interviewers actually test for. Topics include JavaScript internals, React rendering architecture, Node.js event-loop and streams, system design patterns, behavioral interview strategy, resume writing, and salary negotiation. Guides are written at a depth that builds lasting knowledge, not just temporary recall.

What is the JavaScript Playground?

The JavaScript Playground is a free, no-login browser-based code editor powered by Monaco Editor - the same engine that runs VS Code. Code executes in a sandboxed environment with no server round-trip. A live console panel captures console.log, console.error, console.warn, console.info, and runtime exceptions. It supports all ES6+ features: arrow functions, destructuring, async/await, Promises, classes, Map/Set, optional chaining, and nullish coalescing. Press Ctrl+Enter to run. Question pages throughout StackInterview include a Run button that opens the playground pre-loaded with the relevant code snippet so you can experiment immediately.

What are Company Interview Tracks?

Company Interview Tracks simulate the interview format of specific technology companies. Instead of browsing a random question bank, you follow a structured multi-round sequence that mirrors how a real company interviews: increasing difficulty, a mix of technical domains, and questions calibrated to that company's known hiring patterns and culture. It is the closest simulation of a real interview loop you can get without scheduling one. Companies covered include Google, Meta, Stripe, Airbnb, Atlassian, and a growing list of mid-to-large technology companies.

What does a Pro subscription include?

Pro unlocks four things. First, the full coding problems library: all 165 curated DSA problems (free tier gives access to problems 1–40). Second, unlimited AI mock interview sessions with full session history, score trends, and the skill radar chart on your dashboard. Third, the ML-powered Problems Dashboard: Weakness Radar (per-tag accuracy visualization), Company Readiness scores (FAANG readiness estimates from your submission history), For You (personalised problem recommendations), and a 30-day ML-generated study plan. Fourth, access to advanced question datasets across all technologies. The Resume Builder, JavaScript Playground, and the core question bank remain permanently free for everyone.

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