How to Ace a Technical React Interview | Practical Guide

This post is written for engineers preparing for technical React interviews. It focuses on practical routines, mental models and the skills interviewers actually look for, not just “what LeetCode to solve.” Test locally, pick what works for you, and iterate.

TL;DR

• Interviews are multi‑phase: align → plan → implement → optimise. Treat them like tiny product sprints.
• Balance algorithm practice with solid front‑end fundamentals: HTML/CSS, JS, TS, Web APIs, accessibility, and backend APIs.
• Practice narrating your thought process and trade‑offs out loud - interviewers hire people they want to work with.
• Have stories and at least one live project you can walk through end‑to‑end.
• Prepare one modern front‑end topic you can discuss for ~5 minutes.

Interview mental model

Break the interview into clear phases and follow them deliberately:

1. Alignment (0-3 minutes)

   • Don’t go straight into writing code. Ask clarifying questions and repeat the requirements back.
   • Write assumptions and acceptance criteria as comments or quick notes.
   • Confirm constraints (timebox, libraries allowed, edge cases worth handling, accessibility needs).

2. High‑level plan (2-5 minutes)

   • Sketch the approach out loud: components, state shape, data flow and important edge cases.
   • Call out the hardest part first and how you’ll approach it.

3. Implementation (remainder of time)

   • Implement in small increments: write, test, narrate.
   • Pause frequently: “Quick smoke test - does this render?” Ask the interviewer if they’d like a different focus.

4. Optimisation & trade‑offs (last 5-10 minutes)

   • Discuss accessibility, error states, i18n, performance, folder structure and tests.
   • If time allows, implement a small improvement; otherwise explain what you’d do and why.

Always keep the user in mind - will the user see a loader, an error, or a helpful empty state?

What to practise (beyond LeetCode)

LeetCode is great resource, but on the frontend the web basics are essential and often times even more important, so don’t skip knowing the DOM, HTML/CSS, JS, TS, Web APIs, how to consume an API endpoint, etc.

Focus areas:

• DOM & browser fundamentals: event propagation, reflows vs repaints, how layout/CSS affects paint.
• HTML & CSS: semantic HTML, accessibility roles, responsive layouts, CSS architecture (atomic css, BEM, etc…) and sensible class naming.
• React fundamentals: hooks (rules, lifecycles), reconciliation, keys, controlled vs uncontrolled inputs, context trade‑offs.
• State management & data fetching: local state patterns, global state, derived state, optimistic updates, cache invalidation basics.
• HTTP & APIs: request lifecycle, caching headers, when to batch/debounce, error handling strategies.
• Testing: unit tests, integration tests, and testing user flows (not just snapshots).
• Accessibility: focus management, keyboard interactions and shortcuts, ARIA basics.
• Security & performance: XSS vectors, CSP basics, code‑splitting, lazy loading, measuring CLS/LCP/INP and general Web Performance.

Practical habit: pick one area per week and build 30-60 minute exercises you can explain in the interview.

Practice talking about code (how to rehearse)

• Pick 3 projects - (real projects or demos). For each, prepare a 2-3 minute walkthrough covering goal, constraints, architecture, tough trade‑offs and one thing you’d change in retrospect.
• Narration drills - Build a small component you can finish in 30 minutes (e.g. a searchable list with debounce + keyboard nav). Timebox yourself, and narrate every decision aloud - try recording and listening back.
• Pair & mock interviews - do timed runs and ask the pair to interrupt with probing questions.

Simple exercise idea:

• 30‑minute build - a modal that loads remote content and supports keyboard close + focus trap.
• Plan: skeleton → focus management → fetch content → error state → tests.
• Edge cases: network errors, slow 3G, unexpected content height, screen readers.

Have stories and a live project

Interviewers love candidates with real constraints. Even a small real-world project teaches you routing, hosting, performance trade‑offs and client expectations.

When you discuss a project, cover:

• Business goal & success metrics
• Your role and constraints (time, tech, team)
• Architecture & tech choices (why React? why particular bundler?)
• Key trade‑offs you made and why
• Signals of success and one measurable improvement you shipped

Pick one modern front‑end topic and own it

Pick something ‘current’ and be able to discuss it for five minutes. Examples:

• LLM integrations, WebAudio API, WebRTC, Web Components, Server Components, Edge Rendering, CSS Container Queries, or the Intersection Observer.

How to prepare:

• Implement a tiny demo (5-30 mins).
• Know a practical use case, limitations, and one example where you would not use it.
• Prepare two small questions to ask the interviewer about how they use web technologies in their stack.

Bonus: What is the company you are interviewing for doing? What is their main product, build a skinny version of that.

Soft skills matter (practice them)

Hiring rarely chooses the technical perfect candidate over someone with strong collaboration skills. Demonstrate curiosity, passion, humility and empathy.

• Start by asking the interviewer clarifying questions - it shows collaboration.
• When you make an assumption, say it out loud and offer alternatives.
• Use small personal touches: a hobby or a quick one‑line human connection can make you memorable.

Questions to ask the interviewer (examples)

• What does a typical release cycle look like here?
• How is mentorship and career growth handled?
• What does success in the first three months look like for this role?
• Which part of the front‑end stack is currently the hardest to maintain? (good for follow‑ups)

Quick checklist to run before/into an interview

Before interview

• ✅ Know the stack the company uses
• ✅ Have 3 project stories ready
• ✅ One modern topic you can discuss for 5 minutes
• ✅ Practice a 30‑minute build and narration
• ✅ Prepare a list of questions for the interviewer
• ✅ Sleep and hydrate - clear your mind the day before the interview, don’t do much coding and don’t overthink it

During interview

• ✅ Align on requirements
• ✅ Plan high level plan
• ✅ Implement, narrating your thoughts and trade-offs
• ✅ Optimise the solution for production use

Common pitfalls I see and how to avoid them

• Rushing in - don’t start coding before you fully understand the task - ask and repeat the requirements.
• Silence while thinking - narrate. If you need a second, say what you’re mentally considering. Accept given feedback
• Over‑engineering too early - implement smallest useful thing first, then iterate.
• Ignoring accessibility - even a short mention of focus, ARIA and keyboard support scores points.
• Ignoring edge-cases, errors and loading states - Often missed, but are essential for fully working frontend app.

Resources & practice sites

• Timed practice problems (pick React‑specific or UI algorithm problems Frontend Ark)
• Build small demos for modern APIs - explore Figma Community for ideas
• Mock interviews with peers or mentors - Mock interview with me

Final notes - a short routine to try

1. Week 1: pick 3 real projects and prepare walk‑throughs.
2. Week 2: one modern topic - build a demo & learn limits.
3. Week 3: practice 30‑minute builds with narration; do 2 mock interviews.
4. Repeat and iterate - track progress in a simple spreadsheet.

Good interviews are small, focused collaborations. Your job is to be clear, collaborative and pragmatic. Treat the interviewer as a future teammate - that mindset changes what you say and how you show up.