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30 full-stack engineer
interview questions that actually work.
Pulled from the Neuroworx item bank: nine years of calibration against twelve-month performance outcomes on 14,083 full-stack engineers. Sorted by stage (screen, assessment, on-site) and level (IC1 to IC5). Each question comes with what to listen for, what to ignore, and the failure mode it is designed to catch.
30
questions
4
stages
5
levels
14k
hires of validity data
Screen ↓Role-fit ↓On-site ↓Anti-pattern questions ↓
Stage 01 · Screen
Twelve minutes. Ten questions.
The screening conversation. Picked runs this with an AI voice; this is what a human screen would look like with the same rubric. Time-box hard. 60 seconds per answer.
10 questions
01
Tell me about the last feature you took end-to-end. What broke first in production, and what did you do?
ownershipspecificity
Listen for
A feature that touched UI, API, and storage. A real failure mode. A fix with a named trade-off.
Ignore
A feature where they only touched one layer and called it end-to-end.
catches · CV inflation. Features they touched but did not own.
02
Pick a part of your current codebase you think is wrong. Why has it not been fixed?
judgementpolitics
Listen for
A specific module, schema, or API contract. An honest reason for the not-yet (cost, priority, fear of touching it).
Ignore
"Everything is fine." Or a moan about a teammate.
catches · Cannot hold an opinion without making it personal.
03
Walk me through the most recent thing you shipped from spec to production. Spec to deploy.
scopeagency
Listen for
The full arc, across layers. Who they convinced, what they cut, what they migrated. Specific dates.
Ignore
Stack listing.
catches · Engineers who only own the inside of the function.
04
What is the smallest decision you have fought hardest for?
convictiontaste
Listen for
A real example. A retry policy, a column type, a copy choice. They say what they would do differently.
Ignore
Big architecture flexes about microservices.
catches · No discrimination between large and small decisions.
05
Pick a product you use every day and tell me how it probably works end-to-end.
curiositysystems
Listen for
Reasonable guesses across the stack: client, API, datastore, async layer. They name what they do not know.
Ignore
Stack-exchange recital.
catches · Engineers who can only reason about one layer.
06
Last time a teammate disagreed with you in code review. Walk me through it.
commsego
Listen for
A concrete review. Whether they changed their mind, and the moment they did.
Ignore
"I always listen to feedback."
catches · Defensiveness as a personality trait.
07
What is your favourite production bug you have hunted down?
craftwar stories
Listen for
A bug that crossed layers. A specific repro. Their precise role. What changed in the system after.
Ignore
A dramatic story with no resolution.
catches · Engineers who avoid the messy cross-stack debugging.
08
Tell me about a framework, library, or service you tried and rejected.
tastecritical thinking
Listen for
A genuine evaluation. A specific reason to reject. What they used instead.
Ignore
A thing they are "exploring".
catches · CV as the boundary of what they have considered.
09
How do you onboard onto an unfamiliar full-stack codebase?
judgementgenerality
Listen for
A sequence: run it, click one happy path with devtools open, trace one request to the database, find a recent PR, ask one specific question.
Ignore
"I read everything first."
catches · Engineers who freeze without a styleguide.
10
What is one thing you want in your next role that you would not apply for a role without?
stage fitseriousness
Listen for
Something specific. A particular customer base, a particular team shape, a particular kind of product.
Ignore
"Impact." "Growth." "Ownership."
catches · Candidates who are not sure why they are looking.
Stage 02 · Role-fit assessment
A scoped task. A scored rubric.
One realistic task. We score the writeup, not the polish. The candidate has the take-home equivalent of 60 minutes.
8 questions
01
Take this half-finished feature: schema is sketched, API is stubbed, UI exists in Figma. Ship the end-to-end working slice. 90 minutes.
shippingIC2+
Listen for
A working slice across layers in the time. Sensible cuts (no auth, a single happy path). They name what they cut.
Ignore
A perfect schema and no UI. Or a perfect UI and no persistence.
catches · Engineers who cannot make a cut and ship something thin.
02
Here is a 300-line file that spans an API route and its client caller. Refactor it. Three bullets on what you changed and why.
code qualityIC2+
Listen for
A real boundary extracted. Useful naming. Error paths surfaced. The bullets reveal taste.
Ignore
Renaming and adding memoisation.
catches · Cargo-cult refactors.
03
Pick one of three small cross-stack bugs we describe. Reproduce, fix, write the post-mortem. 60 minutes.
craftIC2+
Listen for
How they reach the repro. What they do not touch. The shape of the post-mortem.
Ignore
Time on environment setup. We supply a working dev box.
catches · Engineers who cannot name what they do not know.
04
Sketch the slice for a small feature: a billing usage indicator on the dashboard. Schema, API, UI, and metric. One page.
systems designIC3+
Listen for
A real first cut. They name the metric and the cost. They make a sensible choice about caching.
Ignore
A beautiful architecture diagram with no boring parts.
catches · Engineers who design only at one layer.
05
Estimate the daily cost of running this feature at our current load. Show your working in three sentences.
cost-awareIC2+
Listen for
Reasonable orders of magnitude. They name assumptions. They notice when a number is wrong.
Ignore
Spreadsheets.
catches · Engineers who only know how to build, never how to estimate.
06
Take this real merge request that touches schema, API, and client. Decide if you would approve, request changes, or close. Write the review.
code reviewIC2+
Listen for
Substantive comments across layers. They flag the missing migration step or the unhandled error path.
Ignore
A review focused only on the UI part of the PR.
catches · Reviewers who can only see one layer.
07
Write the change-log entry, the support note, and the metric query for the feature you sketched in question 4.
shippingIC3+
Listen for
A change-log that a customer can read. A support note with the symptoms they would see. A metric that someone could actually run.
Ignore
A change-log copied from the commit message.
catches · Engineers who think shipping ends at deploy.
08
In 200 words, why might the feature you sketched in question 4 be the wrong slice?
humilityIC4+
Listen for
Genuine engagement with the alternative. A real "I should have started smaller" or "I might have batched it".
Ignore
A second pitch for the original design.
catches · Lack of perspective on their own choices.
Stage 03 · On-site (after Picked)
Twelve questions you will still want to ask in person.
Picked screens, scores, and shortlists. These are the questions worth asking with a human in the room: the calibration questions, the dealbreakers, the chemistry probes.
12 questions
01
Where, in the work, do you want to grow most this year?
growthmanager fit
Listen for
A specific gap. A plan, even tentative. A name of someone they would learn from.
Ignore
"I want to become a staff engineer."
catches · Engineers without a learning agenda.
02
Tell me about a time you disagreed with a manager. What happened?
authoritymanager fit
Listen for
A real disagreement. The mechanics, not the moral.
Ignore
"I have never disagreed with a manager."
catches · Engineers who cannot hold opinions in the face of authority.
03
What is the most uncomfortable feedback you have received and what did you do with it?
self-awareness
Listen for
A specific piece of feedback. The change they made. The thing they still struggle with.
Ignore
"I take feedback well."
catches · Defended self-narrative.
04
Walk me through a project you wish had failed faster.
judgementoperating
Listen for
Honesty. A specific moment they could have called it. What stopped them.
Ignore
A pitch for the project being secretly worth doing.
catches · Sunk-cost thinkers.
05
What is a strong opinion you have recently changed?
intellectual humility
Listen for
A specific opinion. A specific cause. They name the source.
Ignore
"My mind is always open."
catches · Closed-loop thinkers.
06
Pick two senior engineers you admire from your last role. What do they do differently?
taste
Listen for
Concrete habits. Habits they have adopted, habits they have not.
Ignore
Pure praise.
catches · Engineers without taste for other engineers.
07
Tell me the last technical thing you read outside your job.
curiosity
Listen for
A specific blog, paper, or talk. They tell you what they thought, not just that they read it.
Ignore
A textbook they "always mean to get to".
catches · Engineers who do not think outside their stack.
08
When are you most productive?
operating model
Listen for
A specific time-of-day and environment. A self-aware answer about energy.
Ignore
"I am always productive."
catches · Engineers without self-instrumentation.
09
Where would you rather be in three years?
careerretention
Listen for
A direction (deeper IC, drifting toward backend or frontend, people-management) and a reason.
Ignore
"Wherever the company needs me."
catches · Drifting engineers.
10
If you join, what would you want your first week to look like?
agencyonboarding
Listen for
A specific plan. Often: ship a 50-line PR, trace one request, sit with a support person for an hour.
Ignore
"Whatever you suggest."
catches · Engineers without an onboarding instinct.
11
What would make you leave us within six months?
dealbreaker
Listen for
A specific irritant. A specific working condition. A specific kind of management.
Ignore
"As long as the work is good."
catches · Hidden dealbreakers, surfaced post-offer.
12
What is one question you want to ask our most cynical engineer?
probingcuriosity
Listen for
A real question. Usually about a quiet thing: "Why is the dashboard slow?" or "What feature does nobody touch?"
Ignore
A softball or a re-pitch of their interest.
catches · Candidates who do not want to know what is wrong.
The anti-pattern set
Eight questions that look smart
but tell you nothing.
"What is your biggest weakness?"
You will get a strength-shaped weakness. We have asked this 47,000 times. It catches no-one. Replace with: "What is the most uncomfortable feedback you have received?".
"Where do you see yourself in five years?"
Either a rehearsed answer or a stalled one. Both useless. Replace with: "Where would you want to be in three years?"
"Tell me about yourself."
Wastes the first three minutes on the CV they already gave you. Replace with: "Walk me through the most recent thing you shipped end-to-end."
"Why this company?"
Generates polished mission-talk. Replace with: "What about this role made you apply that would not have made you apply elsewhere?"
"Are you a team player?"
No-one says no. Replace with: "Tell me about a time a teammate disagreed with you and how you handled it."
"How do you handle stress?"
No-one says badly. Replace with: "Tell me about your last production incident and your precise role."
"How would you reverse a linked list?"
Probes nothing we care about. We removed it from the bank in 2019. Replace with: "Refactor this 200-line file and tell me what you changed and why."
"If you were an animal, which animal would you be?"
You know what we are going to say. Replace with: anything else.
Or, let us ask
We will ask these for you.
By Friday.
Picked runs the screen, the assessment, and the first-round interview against this exact item bank. You meet the three finalists in person, with these on-site questions in hand.
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Full-stack engineer interview questions · Picked.ai