Top 6 Web & Software Developer Interview Questions (2026)

Behavioral questions

Past-experience questions. Answer with the STAR method: Situation, Task, Action, Result.

1. 1

   Tell me about a web project you built from scratch. Walk me through the architecture decisions.

   What they're really asking: Project ownership and decision-making: why this tech stack, how data is stored, how authentication works, how it's deployed, and what you'd change now that it's built. Real project experience reveals more than any technical question.

Technical questions

Skill and knowledge checks. Be specific — name tools, tolerances, and methods.

1. 1

   Explain the difference between the DOM and the virtual DOM.

   What they're really asking: Frontend fundamentals relevant to React/Vue: the DOM is the browser's live representation of the HTML structure; the virtual DOM is a JavaScript object that React maintains as a lightweight copy, using diffing to batch and minimize actual DOM updates for performance.

2. 2

   What happens when you type a URL in the browser and press Enter?

   What they're really asking: Web fundamentals end-to-end: DNS resolution, TCP connection (TLS handshake for HTTPS), HTTP request, server processing, response, rendering (HTML parse, CSS apply, JavaScript execute). This question maps a candidate's mental model of the web stack.

   Strong answer (sequential walkthrough):

   DNS

   The browser checks its cache for the IP address of the domain. If not cached, it queries a DNS resolver, which walks the DNS hierarchy to find the authoritative nameserver and returns the IP.

   Connection

   The browser opens a TCP connection to the server's IP on port 80 (HTTP) or 443 (HTTPS). For HTTPS there's a TLS handshake to negotiate encryption before any data is transferred.

   Request and response

   The browser sends an HTTP GET request with headers (browser type, accepted content types, cookies). The server processes the request and returns an HTTP response with a status code and the HTML body.

   Rendering

   The browser parses the HTML into a DOM, fetches referenced CSS and JavaScript, applies styles to build the render tree, and paints the page. JavaScript execution can block rendering, which is why scripts are often deferred or placed at the bottom of the body.

   Being able to walk this sequence without prompting demonstrates web fundamentals depth that distinguishes candidates who've thought about how the web works from ones who've only used frameworks.

   Practice answering this question out loud →
3. 3

   What's the difference between SQL and NoSQL databases, and when would you choose each?

   What they're really asking: Database selection judgment: SQL (relational, structured schema, ACID transactions, strong for complex queries) versus NoSQL (flexible schema, horizontal scaling, strong for document, key-value, or graph data). The right choice depends on the data model and consistency requirements.

4. 4

   How do you optimize a web page that's loading slowly?

   What they're really asking: Performance optimization toolkit: check the Network tab in DevTools for large assets, compress images, lazy-load below-the-fold content, minimize and bundle CSS/JS, add caching headers, use a CDN, and check for render-blocking scripts. The answer reveals whether the candidate has actually profiled performance issues.

5. 5

   How do you approach cross-browser compatibility issues?

   What they're really asking: Practical frontend experience: checking MDN for browser support, using CSS feature queries, testing in multiple browsers during development rather than at the end, and knowing which properties require vendor prefixes or polyfills.

How to prepare for a Web & Software Developer interview

• 1

  Your portfolio does the interview before you walk in

  Live URLs, clean GitHub repositories, and a brief README explaining each project — employers look before the interview. Make sure every project link works, every repo has a description, and your best work is at the top.

• 2

  Know your framework deeply, not just its syntax

  For React: the component lifecycle, hooks (useState, useEffect, useContext, useMemo), and when to lift state. For Vue: reactivity system and component options API versus composition API. Shallow framework knowledge shows immediately in technical screens.

• 3

  Responsive design and accessibility are increasingly required

  Mobile-first CSS, media queries, and WCAG accessibility basics (semantic HTML, alt text, keyboard navigation, contrast ratios) are expected at most professional roles. They were optional five years ago; they're not now.

• 4

  Ask about their deployment pipeline and technical debt situation

  CI/CD setup, test coverage, and how much of the codebase is legacy tells you what your first year will look like — building new features or maintaining old ones, and how much automated safety net you'll have while doing either.

Web and software developers remain among the most consistently employed technology professionals. Full-stack capability, cloud deployment experience, and React or Vue fluency are the current market differentiators. Developers who can integrate AI tools into their development workflow — using Copilot or Claude for code assistance, code review, and documentation — are measurably more productive and increasingly sought after.