Hardware FixRecommendedDevice not working? Your driver may be the problemCheck updates for common hardware issues.Fix DriversOctober DealsAmazon USOctober deal check: compare before you payAmazon US: current deals, useful picks and tech finds.Check DealsWindows FixRecommendedWindows errors stealing your time? Find the fix fastScan stability, cleanup and performance issues.Fix Now×
Skip to content
World desk5 min

How to Handle a Code Review Interview With a Broken Pull Request

A code-review interview tests how you inspect an existing change, explain concrete risks, and decide what should block a merge—not just how many flaws you find.
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

A code-review interview asks you to inspect an existing change and explain what you would tell a teammate before it ships. In one interview format described by DEV Community author jidonglab, candidates get 30 minutes to review a 180-line pull request aloud. The exercise tests how they gather context, trace behavior, rank risks, and communicate—not how many flaws they can spot.

What is a code review interview?

It is a technical interview built around reviewing a pull request rather than writing a solution from scratch. In jidonglab’s account, the candidate reads an existing diff, narrates their reasoning, asks questions, and decides which findings should block a merge. No new code is written in the example.

As an Amazon Associate I earn from qualifying purchases.

The author says he adopted the format three years before his September 2026 post and had not returned to algorithm questions. That is his account of his own interviewing practice, not evidence that this format is universally better or more predictive. The source provides no hiring-outcome data or controlled comparison with algorithm exercises.

Free tools Windows power users keep installed

One-click scans. No signup required.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

The format can make several skills visible at once: reading unfamiliar code, understanding the change’s goal, tracing risks through the system, and explaining concerns under time pressure. Its value depends on the job, the context supplied, and whether interviewers apply a consistent rubric.

#1 Best Overall
Sale
Cracking the Coding Interview: 189 Programming Questions and Solutions
  • Careercup, Easy To Read
  • Condition : Good
  • Compact for travelling

How the example exercise works

The fictional pull request adds an endpoint for resending verification emails. It includes a route handler, a service class, one migration, and two passing tests. The candidate has 30 minutes to review its 180 lines while talking through questions and findings. Those figures describe the author’s example, not a standard interview length or PR size.

The exercise’s six planted issues illustrate why review is about judgment as well as detection. The author orders them by potential production damage:

  1. User enumeration: An unknown email address gets a 404 no such account, while an address tied to a real account gets 200 sent. The different responses disclose which addresses have accounts.
  2. An unthrottled, user-controlled recipient: Requests can target arbitrary email addresses, creating a potential abuse path through the sending endpoint.
  3. A sliding rate-limit lockout: The limiter rewrites lastAttemptAt even when it rejects a request. Each rejected attempt can move the window forward, potentially keeping a user locked out.
  4. Unsafe migration timing: A migration drops verification_token while older application instances may still read it during a rolling deployment. Those instances can fail until deployment finishes.
  5. A bounded N+1 query: The author treats this as worth commenting on, but not automatically as a reason to block this particular merge.
  6. Style distractions: A leftover console.log and an inconsistent name are low-priority issues in the example, likely to be caught by linting.

These are defects in a fictional exercise, not a claim that a real pull request or every code-review interview contains them.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

What should you do first when reviewing?

Before searching for bugs, establish what the change is meant to accomplish and who can encounter it. That context can change how serious a behavior is and what a useful fix would look like.

  • Ask what the pull request is intended to do and whether the endpoint is user-facing.
  • Clarify relevant assumptions, such as who can make a request and what response the product is supposed to provide.
  • Trace the behavior across repeated requests, not just a single happy-path call.
  • Consider how the code behaves during deployment, when old and new application versions may coexist.
  • Keep the central question in view: what should block this merge, and what merits a nonblocking comment?

These questions help avoid treating every unusual line as equally important. They also give you a basis for explaining a finding instead of announcing a suspected defect without context.

How do you decide what should block the merge?

In jidonglab’s rubric, severity ranking matters more than the raw number of defects found. A strong review distinguishes a concrete risk that warrants stopping the merge from a worthwhile improvement that can be addressed without blocking it. The author’s rubric is one practitioner’s approach, not a validated or universal hiring standard.

For each concern, explain the failure mode and how you would check it. For example, rather than saying only that a rate limiter looks wrong, describe how rejected requests keep advancing the timestamp and propose verifying the behavior with repeated requests around the limit window. This makes the comment actionable and exposes the reasoning behind your priority.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Do not spend a disproportionate share of a short interview on a naming inconsistency or a lint-level issue while higher-impact behavior remains unexplored. In the example, the contrast between account disclosure, endpoint abuse, and style bait is meant to test prioritization—not reward the longest list of comments.

What separates senior candidates in this round?

The source does not establish a general seniority test or independently measure how candidates at different levels perform. In the author’s framing, the useful signals are the quality of the review process: asking for context, thinking through consequences over time, and communicating which issues matter most.

  • They make assumptions explicit. They ask about the PR’s purpose and exposure before treating a behavior as a definite production risk.
  • They follow state over time. They look at repeated attempts and at the interval when old and new instances coexist during deployment.
  • They prioritize impact. They separate a merge-blocking risk from a nonblocking concern and a cosmetic distraction.
  • They make comments verifiable. They describe a concrete failure mode and suggest a way to reproduce or test it.

These are qualities emphasized by this particular interviewer’s account; the post does not provide comparative performance data or evidence about hiring outcomes.

Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Support on Ko-Fi

How do you practice for a code review interview?

Jidonglab suggests choosing an unfamiliar, already-merged pull request from an open-source project and reviewing it aloud for 15 minutes before reading its discussion. Then compare your blocking findings with the maintainer’s comments. The timer and method come from the author’s recommendation; the source does not establish that this drill improves interview outcomes.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
  1. Pick a merged pull request in a language or project you can follow but do not already know well.
  2. Read the diff and narrate what the change appears to do. Note questions you would ask the author.
  3. Set a 15-minute timer and identify the risks you would raise, distinguishing blockers from other comments.
  4. Only after your review, read the pull-request discussion and compare your reasoning with the maintainer’s feedback.

Focus on whether your explanation names a plausible failure and gives a way to verify it, rather than on matching every comment in the discussion. The exercise is practice in both technical analysis and narrating your reasoning.

How does this differ from an algorithm interview?

A code-review round observes how you read, question, and assess an existing change; an algorithm exercise commonly centers on producing a solution. That difference may make review relevant to work involving pull requests, but the source offers no controlled evidence that one format predicts job performance better than the other.

When evaluating an interview format, consider whether it reflects the role, which skills are actually observed, how much realistic context candidates receive, how time pressure affects the task, and whether interviewers use a consistent rubric. The author argues for his format from personal experience, not a general comparative study.

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Leave a Reply

Your email address will not be published. Required fields are marked *

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

More from the Wire

  1. World desk4 min
    How to Spot an AI Voice Scam Before Sending MoneyDon’t rely on how a caller sounds. Pause, call back through a known number, and verify the emergency with another trusted person before sending money.
  2. Mountain View desk4 min
    Google’s SynthID Detector: How to Check AI-Generated Images, Video and AudioGoogle’s SynthID Detector looks for an embedded watermark in supported images, video and audio. Here is what its results do—and do not—show.
  3. Redmond desk20 min
    How to create a link to File or Folder in Windows 11Windows 11 gives you several ways to point to a file or folder without moving or duplicating it. You can create a desktop shortcut,…
Recommended PC Tool
Recommended PC Tool
PC Slower Than It Used to Be?Free scan - under a minute
Crashes, No Sound, or Screen Glitches?Free driver scan

Two free Windows tools

One Free Minute Could Fix That PC

Before you go - each of these free tools takes about a minute and tackles what quietly slows a Windows PC down.

Special offer. View Outbyte info, uninstall instructions, EULA, and Privacy Policy.