Your developer interview preparation hub

Prepare for your next tech interview. Start for free.

Practice real developer interview questions, solve coding challenges, and walk into your interview prepared. When you're ready, go further with AI-powered mock interviews.

Explore free interview questionsStart coding practice
Or try an AI mock interview
  • Free interview questions
  • Coding practice with test cases
  • 9 technologies & multiple job roles
devvlt.com/interview/language-specific
JavaScriptEasyConceptual

What is the difference between == and === in JavaScript?

More JavaScript questions
Coding challengeEasy

Two Sum

Arrays & Hashing · 2 test cases

twoSum(nums, target)

Solve it free

Free practice tools

Everything you need to prepare — for free

Explore developer interview questions, practice coding, and build confidence at your own pace.

Free

Language-specific questions

Study the concepts interviewers actually probe — from closures and the event loop to rendering, routing, and version control — with answers and code examples.

  • HTML5
  • CSS
  • JavaScript
  • React
  • Java
  • Next.js
  • Node.js
  • Git
  • Data Analytics
Explore technologies
Free

Role-based interview questions

Question sets organized around the job you're targeting.

  • Frontend Developer
  • Sharepoint Developer
  • Mulesoft Developer
  • Data Scientist
Browse job roles
Free

Coding challenges

50 problem-solving exercises with hints. Write your solution in the browser and run it against test cases.

Run in: JavaScript · TypeScript · Python · Java · C# · PHP

Start coding

No sign-up needed to start: preview the first 5 questions in every topic and the first 6 coding challenges. A free account unlocks all of them.

Explore by technology

Master your favorite tech stack

Pick a technology and go deep. Every topic opens a free, searchable set of interview questions.

View all technologies

Role-based preparation

Prepare for the role you want

Interview question sets organized around real job titles, so you can focus on what that role is likely to be asked.

Browse all roles

Coming soon

  • Backend Developer
  • Full-Stack Developer
  • DevOps Engineer
  • Software Engineer
  • Cloud Engineer
  • Mobile Developer
  • UI/UX Designer
  • Cybersecurity Specialist
  • Data Analytics

How DevVlt works

Your interview preparation journey starts here

  1. 01

    Choose your path

    Pick a technology, a programming language, or the job role you're interviewing for.

  2. 02

    Practice and improve

    Work through interview questions with answers, then solve coding challenges against real test cases.

  3. 03

    Get interview ready

    Walk in confident. When you want extra reps, add AI mock interviews and a personalized study plan.

    AI practice is optional

DevVlt AI · Next step

Ready to take your preparation further?

Practice realistic interviews and create personalized preparation plans with DevVlt AI.

Requires a free account. Each session uses 5 credits, and new accounts include 5. See pricing

AI mock interview

Rehearse with an interviewer that listens

Answer each question in your own words, get follow-ups based on what you said, then review a report of how you did.

  • Technical interview simulation
  • Behavioral interview practice
  • Follow-up questions
  • AI feedback & performance report
Explore AI interviews

AI job prep planner

Turn a job description into a study plan

Paste the posting (and optionally your resume). DevVlt pulls out the key skills and builds preparation around them.

  • Job-description-based preparation
  • Personalized interview questions
  • Relevant coding practice
  • Structured day-by-day roadmap
Create your study plan

Why developers use DevVlt

Built for focused, honest practice

No gimmicks — just the material you need to prepare, in one place.

13Question topics
9 technologies and 4 job roles, organized so you can find the right practice fast.
50Coding challenges
Problems with examples, hints, and test cases you can run directly in the browser editor.
AnswersNot just questions
Questions come with explanations and code examples, so you learn the why, not only the what.
$0To start practicing
The question library and coding challenges are free. AI features use transparent, credit-based pricing.

FAQ

Questions, answered

Can't find what you need? Contact us.

Is DevVlt free to use?
Yes. The interview question library and coding challenges are free. AI-powered features — mock interviews and the job prep planner — run on credits, and paid plans or credit packs are available if you need more.
Can I practice interview questions without signing up?
Yes. Without an account you can preview the first 5 questions in every topic and the first 6 coding challenges. Creating a free account unlocks all questions and challenges.
Which programming languages and technologies are supported?
Interview questions currently cover HTML5, CSS, JavaScript, React, Java, Next.js, Node.js, Git and Data Analytics. In the coding challenge editor you can write and run solutions in JavaScript, TypeScript, Python, Java, C# and PHP.
Can I prepare for frontend and backend interviews?
Role-based question sets are available today for Frontend Developer, Sharepoint Developer, Mulesoft Developer and Data Scientist. More roles, including Backend Developer, Full-Stack Developer and DevOps Engineer, are coming soon. For backend fundamentals in the meantime, the Node.js and Java topics are a good place to start.
How does the AI mock interview work?
Choose a technical or behavioral interview (with an optional pressure mode). The AI asks questions, follows up based on your answers, evaluates each response, and finishes with a performance report highlighting strengths and areas to improve. It requires a free account.
What is included in the free plan?
A free account gives you full access to the interview question library and all coding challenges, plus 5 AI credits — enough for one AI mock interview or one AI job prep plan. See the pricing page for current plan details.
Do AI features require credits?
Yes. Each AI mock interview session and each AI job prep plan uses 5 credits. You can get more credits with a paid plan or a one-time credit pack on the pricing page.

Your next interview starts with better preparation.

Explore free questions, practice coding, and take the next step toward your developer career.

Start preparing for freeExplore AI practice