Hiring a software engineer can feel like sorting through a pile of resumes, running interviews that show technical skill but not how someone will work with the team, and hoping you did not miss a red flag. Suppose you want to learn how to interview a software engineer and consistently hire people who write solid code and fit your culture. In that case, this guide outlines practical steps, including resume screening, focused technical tests and coding challenges, system design conversations, behavioral interview questions, pair programming exercises, and a scoring rubric for fair candidate evaluation.

To make that easier, Noxx's AI recruiter helps you write clear interview questions, score resumes and coding tests, run consistent interview loops and scorecards, and surface candidates who match your team so you can hire with confidence. It can also suggest pair programming tasks and guide interviewers on giving fair, actionable feedback.

Table of Contents

• How to Interview a Software Engineer

• Tips to Conduct a Flawless Software Engineer Interview

• Upload a Job and Get 10 Candidates within 7 Days with Noxx (No Risk, No Upfront Fees)

Summary

• Interviews work best as a short diagnostic, rather than a comprehensive exam, since a 45- to 60-minute session cannot accurately assess long-term job performance and is more effectively used to observe problem-solving and recovery under time pressure.  

• Frame each interview around four practical questions you want answered in one hour: can the candidate ship code, reason about it with peers, handle surprises, and be someone you want to work with.  

• Design tasks to mirror real work, because 70% of companies use coding challenges and 85% of engineers prefer technical interviews that include real-world problem-solving, which increases the chance you see collaboration and maintenance skills rather than memorized algorithms.  

• Force evidence-based notes by capturing three items right after the session, namely one objective timeline, two direct evidence points tied to rubric items, and the hire or no-hire call, which shifts debates from impressions to verifiable signals.  

• Reduce bias and variance with light calibration, for example, by calibrating interviewers on one to two recorded sessions per quarter and requiring paired evidence before a no-hire decision. Additionally, run a five-minute systems check to save 10 to 15 minutes of lost observation time.  

• Prefer short, well-scoped take-home projects paired with a 30- to 60-minute live validation, as 85% of candidates in recent reporting said they prefer take-homes over traditional algorithm tests. This combination preserves pipeline speed while surfacing system-level thinking.  

• This is where Noxx's AI recruiter comes in, by suggesting rubric-linked interview questions, consistently scoring resumes and coding tests, and running standardized interview loops that surface candidates who match the team's evaluation signals.

How to Interview a Software Engineer

Interviewing a software engineer is a structured, evidence-based process, including preparing realistic, multi-stage tasks, running a time-boxed hands-on coding session where the candidate writes, executes, and debugs code, and then recording objective notes tied to the four hiring questions, allowing for a clear hire or no-hire decision. Do the hard work up front, task design, calibration, and a rubric, and the hour in the room becomes a controlled experiment rather than a guessing game.

What Are the Goals of the Programming Interview?

We ask four concrete questions: 

• Will the candidate write working code?

• Can they discuss that code with teammates?

• Can they reason under constraints?

• Will you enjoy working with them?

Example

A back-end hire should demonstrate the ability to read and modify existing code, while a front-end hire should wire up a small UI and handle state management.

• Do: Make those goals explicit on the rubric and map each interview stage to one or two goals.

• Don’t: Treat finishing a single algorithm as a proxy for all four answers.

What Tactical Choices Increase Signal?

Prioritize realism, set candidates up to succeed, and maximize candidate-work time. For realism, prefer debugging, refactoring, or adding features to small runnable programs over abstract algorithm drills.

Example

Instead of asking for a whiteboard mergesort, ask them to extend a tiny in-memory cache so it evicts correctly under concurrency.

• Do: Provide working stubs and test harnesses.

• Don’t: require memorized API minutiae or force artificial constraints that never occur in production.

What Are the Limits and Non-Goals of the Interview?

Random chance and time are real constraints. A quick solution could be due to luck or prior exposure, and 40 to 60 minutes will never capture long-term judgment work. Use tasks with multiple decision points so one lucky shortcut does not determine the result. Non-goals to avoid are nitpicking syntax, making life intentionally hostile, or treating the interview as a trivia contest; instead, treat it as an opportunity to watch how someone engineers under pressure.

What Practical Constraints Should You Plan For?

• Randomness: Design tasks that admit multiple valid approaches so the solution pathway reveals process, not recall.

• Time: expect most interviews to be under an hour, and use follow-ups or take-home stages when you need a deeper signal.

• Example: A two-stage on-site where stage one is a runnable parser, stage two adds variable support, gives you contiguous evidence of thinking and refactoring.

How Do You Pick and Stage the Task?

Pick messy, open-ended tasks that force design choices and iterative improvements. Example tasks: 

• A simple templating engine

• A parallel web scraper

• A mini interactive UI

Break work into stages so strong candidates stay busy and everyone shows refactoring and recovery skills.

• Dos: Prepare extension steps in advance and have measured time expectations.

• Don’ts: Hand a single, trivial problem with no natural follow-ups.

How Should You Validate the Interview Task?

Before fielding the question, test it on one or more colleagues under timed conditions and document typical completion times, common pitfalls, and alternate solutions. When we conducted these rehearsals for a library of questions, we captured multiple baseline solutions and reduced post-interview calibration time by ensuring scoring consistency across interviewers.

• Do: Record objective checkpoints like “stage one completed in 20–30 minutes.”

• Don’t: Skip testing and expect uniform candidate experience.

When the Candidate Arrives, How Should You Start?

State the agenda up front, like resume chat, coding, Q&A, and time buffers. Clearly separate what you provide from what you expect them to deliver, and hand them a printed problem description that contains background, constraints, and examples so they can refer to it while coding.

• Do: Allocate a short buffer at the top for settling in.

• Don’t: Leave ambiguity about expected outputs or runtime guarantees.

What Should the Coding Session Look Like?

Have candidates type their code into an editor and run it. Executing code turns subjective squinting into reproducible evidence, providing an immediate debugging signal.

Example

Ask them to write a serialization routine, run it against provided tests, and then add an extension.

• Do: Provide a runnable harness and allow them to use reasonable documentation.

• Don’t: Force whiteboard-only solutions that obscure how they actually work in practice.

Should Candidates Run and Debug Code?

Yes. Let them run tests, read stack traces, and apply standard debugging techniques. This exposes how they diagnose and fix problems, not just if they can recall an algorithm. Treat it like watching a mechanic under the hood, not a theatrical performance.

• Do: Allow them to use print-debugging, REPLs, and test cases.

• Don’t: Refuse execution because you want to “test pressure handling.”

How Should Interviewers Behave While They Work?

Let candidates make mistakes and minimize interruptions, but be ready to nudge when there is absolutely no signal. If you must interrupt, choose natural stopping points or batch questions so you do not fragment thinking. 

• Dos: Pause to ask why they chose an approach after a stage completes.

• Don’t: Correct every minor misstep mid-line.

Watching a candidate rescue broken code teaches you more than watching them avoid all errors.

How Do You Write Objective Feedback After the Interview?

Capture a timeline of what happened, including measurable checkpoints and subjective impressions, tied to concrete examples. For instance, record minutes when a candidate fixed a bug, or when they refactored to add a feature; pair those with short evaluations like “recovered from index-out-of-range in 6 minutes by adding bounds checks and unit tests.” Use objective facts to justify subjective calls so post-interview calibration converges quickly.

How Do Common Practices and Expectations Shape Candidate Experience?

The Tech Recruitment Survey 2023 reports that 70% of companies use coding challenges as part of their interview process, indicating that these exercises are standard and therefore worth designing well. Glassdoor Economic Research indicates that, on average, it takes 23 days to complete the interview process for a software engineering position, underscoring the importance of efficient upstream screening and rapid shortlist validation. Expect candidates to feel interview fatigue; design respectful sessions that maximize signal and minimize theatrical stress.

What Are Specific Dos and Don’ts You Can Apply Immediately?

Do: 

• Use runnable, multi-stage tasks

• Test questions on colleagues

• Give clear constraints

• Record objective checkpoints

• Let candidates execute and debug

Don’t:

• Default to whiteboards

• Nitpick inconsequential style in a timed session

• Make the interview adversarial

• Use a single-pass problem that induces high randomness

A good interview is a professional, humane experiment that produces reproducible evidence.

What Should the Hiring Decision Depend On?

Base the hire/no-hire call on the four primary answers, supported by objective notes and multiple interview touchpoints when possible. If a candidate demonstrates fluent debugging, clear communication, sound trade-offs, and a collaborative temperament during your session, the interview has done its job. If not, the write-up should specify which of the four questions failed and why, including timestamps and artifacts to support a defensible decision.

Related Reading

• Software Engineer Recruitment Agencies

• How to Assess Programming Skills

• Software Engineering Behavioral Questions

• Managing Remote Developers

• Developer Skills Assessment

• How to Interview a Software Engineer

Tips to Conduct a Flawless Software Engineer Interview

Eliminate friction before the clock starts, prime the conversation with empathy, and collect tightly scoped evidence you can map back to the hiring bar. When those three things happen, interviews finish with a clear hire or no-hire, and both sides leave knowing where they stand.

What Should I Verify Before the Candidate Joins?

Arrive early, and run a five-minute systems check that covers the candidate’s preferred editor, a working terminal or browser, network access, and a loaded test case you can run. Confirm that screen sharing permissions are enabled and that any required language runtimes or package managers are accessible. Have a backup plan ready, such as a shared pastebin link or a whiteboard photo option, in case the video fails to load. Practically, this saves a lost 10–15 minutes that otherwise eat into the observation window.

How Do I Calm Things So Candidates Perform Closer to Their Baseline?

Acknowledge the stress with one sentence, then give a micro-structure: “We’ll spend 30 minutes on the problem, 10 minutes debugging, and 5 minutes for your questions.” Offer a one-minute reset if they freeze, such as rephrasing the core requirement, asking them to list two or three assumptions aloud, and then asking which one they would change first. When we coached new interviewers over an eight-week program, this simple framing reduced rambling and produced clearer, testable steps within the first 10 minutes.

What Short Prompts Reveal Real Thinking Without Wasting Time?

Use three tight probes that map back to your rubric:

• “What would you change if this had to scale 10x?” looks for tradeoffs and systems sense

• “Name one assumption that, if false, breaks your approach” tests risk awareness

• “Show me the smallest test that would convince you this works” exposes engineering hygiene and pragmatism.

These questions force candidates to convert intuition into evidence, and they give you verifiable anchors for post-interview notes.

How Do You Triage When the Candidate Is Off the Expected Level?

If they appear overqualified, switch to a collaboration and leadership probe. Ask for an example of delegating a difficult refactor or how they transfer ownership of a subsystem. If they seem underqualified, pivot to problem decomposition and learning velocity. Ask them to break the problem into three milestones and describe the first experiment they would ship.

Use a Short Decision Rule

If the candidate hits two of your rubric’s core behaviors within the allotted time, they stay in contention; if not, treat this as a learning signal for the recruiter rather than an immediate rejection.

Why Prefer Short Take-Home or Real-World Tasks as Part of the Workflow?

Given that The Underdog.io Team reports 85% of candidates prefer take-home projects over traditional algorithm tests, offering a short, well-scoped take-home project reduces anxiety and shows how candidates work in their environment. That format, when paired with a thirty- to sixty-minute live validation, preserves the speed of the pipeline while surfacing system-level thinking that a whiteboard cannot.

How Do Interview Notes Become Decisions That Scale Across Teams?

Capture three things immediately after the session:

• One objective timeline (key actions with timestamps)

• Two direct evidence points are tied to rubric items

• Your hire/no-hire call with an explanatory sentence

This forces discussions to start from evidence. For close calls, require one recorded example from another interviewer before you flip a no-hire. That rule reduces rework and shortens debriefs into decisive outcomes.

How Do You Frame Your Closing Lines So Both Parties Leave Clear?

End by stating one sentence about fit. A concrete, evidence-backed claim such as, “You demonstrated clear ownership of debugging and sensible tradeoffs, but you missed two core rubric items for this level.” Then, invite questions and indicate when the recruiter will follow up. That blunt, yet kind, close removes the awkwardness of vague feedback and preserves dignity for both parties.

Related Reading

• Average Time to Hire Software Engineer
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• Software Developer Performance Metrics
• Software Developer Job Description Example
• How to Conduct Online Coding Test
• Developer Screening

Upload a Job and Get 10 Candidates within 7 Days with Noxx (No Risk, No Upfront Fees)

If you want faster, lower-risk technical hires, try Noxx. It delivers a compact, curated shortlist of 10 candidates within 7 days, allowing you to validate the fits with brief, focused interviews. You only pay when you hire, with a 1% success fee, which keeps costs predictable while you decide who belongs on your team.

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