Question 1
Which flow in this job has to work with a keyboard and a screen reader, and how would you check it?
Approach. Name the control, the expected announcement, and the check you would do before shipping.
Frontend engineer interview questions from a job description
Turn a frontend engineer job description into likely React, CSS, accessibility, and behavioral questions, with a one-line approach for each.
Matched in your browser from the requirements in the posting and Luna’s interview-question hub. These are practice prompts, not a claim that this wording will be asked.
Requirements in the posting
Frontend Engineer
You will build the web app our customers use every day.
Responsibilities:
- Ship React and TypeScript UI, including loading and error states
- Write CSS and HTML that stay coherent on small screens and in responsive layouts
- Treat accessibility as part of the feature: keyboard, focus, and screen reader paths
- Work in JavaScript without hiding behind a framework when the DOM is the right tool
- Partner with design and backend engineers and own the frontend quality of what you ship
You are comfortable explaining why state lives where it lives.
You will build the web app our customers use every day.
Responsibilities:
- Ship React and TypeScript UI, including loading and error states
- Write CSS and HTML that stay coherent on small screens and in responsive layouts
- Treat accessibility as part of the feature: keyboard, focus, and screen reader paths
- Work in JavaScript without hiding behind a framework when the DOM is the right tool
- Partner with design and backend engineers and own the frontend quality of what you ship
You are comfortable explaining why state lives where it lives.
Likely questions
Role
Accessibility
Treat accessibility as part of the feature: keyboard, focus, and screen reader paths
Question 2
Tell me about an accessibility fix that changed the design, not just the markup.
Approach. Describe the user’s block, the design change, and what you gave up to make the action clear.
Coding
CSS and interface
Write CSS and HTML that stay coherent on small screens and in responsive layouts
Question 3
How would you build a responsive layout for the main screen in this posting without a framework?
Approach. Name the layout method and the breakpoint that worries you, then one case you would check in the browser.
Question 4
Tell me about a UI bug that was really a layout or event bug. How did you prove the cause?
Approach. Say what you inspected, what you ruled out, and the change the user could see.
Coding
JavaScript
Work in JavaScript without hiding behind a framework when the DOM is the right tool
Question 5
Walk through a JavaScript function you would write for this role and the bug you would check before calling it done.
Approach. Restate the input, give the naive version, then name one edge — empty, duplicate, or async — and how you would prove it.
Question 6
When would you reach for a plain object, a Map, or an array, and what does that choice cost?
Approach. Tie the structure to the access pattern in the posting, and say the time cost of the common operation.
Coding
TypeScript
Ship React and TypeScript UI, including loading and error states
Question 7
Where would types earn their keep in this job, and where would they just slow a change down?
Approach. Name one boundary — an API payload or a shared component — and one place you would keep the type loose on purpose.
Coding
React
Ship React and TypeScript UI, including loading and error states
Question 8
Sketch a React component this posting would need. What state is local, and what is passed in?
Approach. Start from the user action, name the state, and say what you would not put in state.
System design
Backend services
Partner with design and backend engineers and own the frontend quality of what you ship
Question 9
Where would you draw the service boundary for this product, and what would you keep in one process for now?
Approach. Start from the request that must be fast, then name the split you would postpone.
Behavioral
Collaboration
Partner with design and backend engineers and own the frontend quality of what you ship
Question 10
Tell me about a disagreement with someone who did not report to you. What did you do with their objection?
Approach. Name the objection, what you changed, and what you did not. Do not flatten it into “we aligned.”
What to prepare
- Tab through one flow with your eyes off the screen and note the first place focus gets lost.
- Practice one layout out loud: the constraint, the CSS you would write, and what breaks on a small screen.
- Rehearse one array transformation out loud, including the empty case and the cost.
- Pick one function and say which types you would write, and which you would leave inferred.
- Rebuild one component from a blank file and narrate where state lives.
- Draw one service boundary and say what you would not split out yet.
- Have one story where someone disagreed and you kept the working relationship.
Frontend postings hide the interview in the stack list. React and CSS mean a UI exercise more often than a puzzle about graphs. Accessibility, if it is a real bullet and not a slogan, becomes “tab through it and say what the screen reader should announce.” TypeScript shows up as a question about where types help and where a cast is hiding a bug.
Ignore the brand adjectives and mark the user-facing verbs: layout, state, loading, error, keyboard. Each of those is a question. “Pixel perfect” without a user is weaker signal than “works on a small screen” or “accessible.”
Bring a component you can rebuild from memory and a layout bug you can narrate. The sample posting is a product UI role. The highlighted lines are the ones a frontend loop usually turns into prompts.
Sample job description
The posting below is already in the tool. The questions are the ones its requirements point to. Replace it with a posting you are actually interviewing for.
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