Question 1
What tables would you need for the core object in this posting, and what is the grain of each?
Approach. Name the entity, the key, and one query you must keep fast.
Full-stack engineer interview questions from a job description
Map a full-stack job description to the UI, API, and product questions interviewers tend to ask, with a short 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
Full-stack Engineer
Build features from the React UI through the API to the database.
You will:
- Implement product flows in React, TypeScript, and CSS
- Design the REST API those screens call, including errors the UI can show
- Write SQL against Postgres and keep the schema understandable
- Use JavaScript on both sides when that is the simplest path
- Own features end to end and collaborate with design when the contract is unclear
We will ask you to narrate a change that touched more than one layer.
Build features from the React UI through the API to the database.
You will:
- Implement product flows in React, TypeScript, and CSS
- Design the REST API those screens call, including errors the UI can show
- Write SQL against Postgres and keep the schema understandable
- Use JavaScript on both sides when that is the simplest path
- Own features end to end and collaborate with design when the contract is unclear
We will ask you to narrate a change that touched more than one layer.
Likely questions
Coding
SQL and data modeling
Write SQL against Postgres and keep the schema understandable
Question 2
Write the shape of a query this team would run every day. Where would it get slow?
Approach. Say the join, the filter, and the index or rewrite you would try first.
Coding
React
Build features from the React UI through the API to the database.
Question 3
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.
Question 4
Tell me about a render bug — stale data, a bad key, or an effect that ran too often. How did you fix the cause?
Approach. Describe what the user saw, the wrong update, and the smaller fix you kept.
System design
APIs
Design the REST API those screens call, including errors the UI can show
Question 5
Design the API a client of this product would call first. What is the request, the success, and the error?
Approach. One resource, the idempotency story, and what the user sees on a timeout.
Question 6
How would you change this API without breaking clients that are already shipped?
Approach. Say what you would version or add, and the client you refuse to strand.
Coding
JavaScript
Use JavaScript on both sides when that is the simplest path
Question 7
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.
Coding
TypeScript
Implement product flows in React, TypeScript, and CSS
Question 8
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
CSS and interface
Implement product flows in React, TypeScript, and CSS
Question 9
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.
Behavioral
Collaboration
Own features end to end and collaborate with design when the contract is unclear
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
- Practice one join out loud: the grain of the result, then the filters.
- Rebuild one component from a blank file and narrate where state lives.
- Write one endpoint on paper: method, body, error, and what a retry should do.
- 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.
- Practice one layout out loud: the constraint, the CSS you would write, and what breaks on a small screen.
- Have one story where someone disagreed and you kept the working relationship.
Full-stack postings are two loops stapled together. The risk is preparing only the half you like. If both React and an API appear as real work, expect a question that crosses the boundary: what the UI shows when the request fails, and who owns that contract.
Mark every bullet that names a layer. A posting that says “full stack” but only lists frontend tasks will still interview the frontend. A posting that adds Postgres and service ownership will ask about the data and the after-launch.
Have one story that starts in the interface and ends in the data, with you as the person who noticed the mismatch. The sample below is that kind of role.
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.
Related: Google coding questions · Meta coding questions · API design starter