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Brex·Software Engineer·Onsite - Behavioral / Leadership·Senior

Senior
May 2026

Summary

Behavioral round at Brex for a software engineering role. Pretty standard set of questions but a few of them pushed harder than I expected, especially the ones around production incidents and conflict.

Questions Asked (5)

Q1

Tell me about a time you had to work through a problem that was poorly defined or had no clear right answer.

Adaptability & Ambiguity
Author's notes

This is the one I fumbled a bit.

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AI HintsAI Generated

Suggested Approach

Choose a specific project where requirements were vague or conflicting, and walk through how you brought structure to the ambiguity. Focus on the actions you took to clarify the problem, make trade-offs, and deliver a solution, rather than just describing the chaos.

Pro tip: Emphasize how you proactively sought input from stakeholders or data to define success criteria, and show that you can make decisions with incomplete information while remaining adaptable.

1. Set the Context

Briefly describe the project, the ambiguity you faced, and why it mattered. Keep it concise to focus on your actions.

2. Clarify the Problem

Explain how you gathered information, asked questions, and worked with others to define the problem and success criteria.

3. Evaluate Options and Make Trade-offs

Describe the alternatives you considered, the criteria you used to choose, and how you handled uncertainty.

4. Execute and Adapt

Detail the steps you took to implement your solution, including how you monitored progress and adjusted as new information emerged.

5. Reflect on Outcomes and Learnings

Summarize the results, what you learned about navigating ambiguity, and how you would apply that learning in the future.

Key Points to Mention

  • How you identified and engaged key stakeholders to align on goals
  • The specific techniques you used to break down the ambiguity (e.g., user research, prototyping, data analysis)
  • The trade-offs you made and the rationale behind them
  • How you communicated progress and decisions to keep the team aligned
  • The measurable impact or outcome of your solution
  • What you would do differently next time to handle ambiguity even better

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

Walk me through a serious production issue you debugged. How did you communicate with the team while it was still happening?

Root Cause AnalysisStakeholder Management
Author's notes

This one actually went well for me.

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AI HintsAI Generated

Suggested Approach

Choose a specific, high-impact production issue and narrate it as a structured story: detection, triage, root cause, fix, and follow-up. Emphasize how you kept stakeholders informed with regular, concise updates and how you balanced debugging with communication.

Pro tip: Show that you communicated proactively before being asked, and that you tailored updates to different audiences (e.g., engineers vs. non-technical stakeholders). This demonstrates ownership and empathy under pressure.

1. Set the context

Briefly describe the system, the impact of the issue, and why it was serious (e.g., affected payments, caused downtime). Keep it concise to focus on your actions.

2. Detection and initial response

Explain how you became aware of the issue (alert, customer report) and your immediate actions: acknowledging, assembling a response team, and starting an incident channel.

3. Debugging and root cause

Walk through your systematic debugging process: forming hypotheses, testing, and isolating the root cause. Highlight collaboration with teammates and use of tools.

4. Communication during the incident

Detail how you communicated: frequency (e.g., every 30 minutes), channels (Slack, email), and content (status, impact, ETA). Mention how you kept non-technical stakeholders informed without overwhelming them.

5. Resolution and follow-up

Describe the fix, verification, and post-mortem. Emphasize blameless retrospective, action items, and how you shared learnings with the team.

Key Points to Mention

  • Specific impact metrics (e.g., number of users affected, revenue loss, downtime duration)
  • Use of monitoring/alerting tools (e.g., Datadog, Prometheus) for detection
  • Clear, regular communication cadence with stakeholders
  • Collaboration with team members and cross-functional partners
  • Root cause analysis techniques (e.g., 5 Whys, fishbone diagram)
  • Post-incident actions: blameless post-mortem, documentation, preventive measures

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q3

Describe a situation where you had a real disagreement with a teammate. How did it get resolved?

Conflict Resolution
Author's notes

Went fine.

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AI HintsAI Generated

Suggested Approach

Choose a genuine technical disagreement where you and a teammate had different approaches, and focus on how you separated the problem from the person. Show that you listened, used data or prototypes to evaluate options, and reached a resolution that improved the outcome—even if your original idea wasn't chosen.

Pro tip: Emphasize that you sought to understand your teammate's reasoning before advocating for your own, and mention that you documented the decision and rationale so the team could move forward aligned. This signals maturity and strong engineering collaboration.

1. Set the context briefly

Describe the project, your role, and the teammate's role in 1-2 sentences so the interviewer understands the stakes and the technical domain.

2. Explain the disagreement objectively

State both positions fairly—what you proposed and what your teammate proposed—and why each seemed reasonable at the time.

3. Show how you explored the options

Describe the steps you took to resolve it: listening, asking questions, gathering data, building a small prototype, or running a spike to compare approaches.

4. Reveal the resolution and outcome

Explain what was decided, how you aligned as a team, and the measurable or qualitative impact on the project.

5. Reflect on what you learned

Share a brief lesson about collaboration, communication, or technical decision-making that you've applied since.

Key Points to Mention

  • Active listening and asking clarifying questions to understand their perspective
  • Using data, benchmarks, or a small prototype to make the decision objective
  • Keeping the discussion focused on the problem, not personal preferences
  • Involving a tech lead or the team when consensus was hard to reach
  • Committing fully to the final decision even if it wasn't your first choice
  • Documenting the decision and rationale for future reference

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q4

What's a meaningful mistake you made and what changed because of it?

Adaptability & Ambiguity
Author's notes

I blanked for a second and almost went with something too small and safe.

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AI HintsAI Generated

Suggested Approach

Choose a real, meaningful mistake that had clear consequences and led to a specific change in your behavior or process. Structure your answer to show ownership, the impact, and the concrete steps you took to prevent recurrence, emphasizing how it made you a more effective engineer.

Pro tip: Avoid mistakes that are too trivial or too catastrophic; pick one where you can clearly articulate the trade-off you missed and the systematic change you implemented. Show that you turned the mistake into a learning opportunity that benefits your team, not just yourself.

1. Set the context

Briefly describe the project, your role, and the situation so the interviewer understands the stakes and your responsibilities.

2. Describe the mistake

Clearly state what you did wrong, without deflecting blame or minimizing it. Explain the immediate impact and why it mattered.

3. Own the consequences

Acknowledge the negative outcomes and how you took responsibility for fixing or mitigating them. Show accountability.

4. Explain the change

Detail the specific actions you took to prevent the mistake from happening again, such as new processes, tools, or habits.

5. Highlight the lasting impact

Describe how this change improved your work or your team's effectiveness over time, and what you learned about yourself as an engineer.

Key Points to Mention

  • A specific technical or process mistake with real consequences
  • Clear ownership and accountability for the error
  • The immediate impact on the project, team, or users
  • Concrete steps taken to remediate and prevent recurrence
  • Systematic or cultural change implemented (e.g., new testing practice, code review guideline)
  • Long-term positive outcome or lesson that made you a better engineer

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q5

Why are you interested in this role specifically, and where do you see yourself going longer term?

Product Strategy
Author's notes

Standard closer.

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AI HintsAI Generated

Suggested Approach

Connect your interest in Brex to its mission and products, showing you understand the company's unique position in fintech and how your skills align with the role. Then, articulate a long-term vision that demonstrates ambition and commitment to growth within Brex, linking your personal development to the company's success.

Pro tip: Research Brex's recent product launches or strategic moves and mention them specifically to show genuine interest; avoid generic answers about 'wanting to work for a fintech leader'.

1. Show company knowledge

Mention specific Brex products, recent news, or cultural values that resonate with you, demonstrating you've done your homework.

2. Align with role

Explain how the Software Engineer role at Brex fits your skills and interests, citing specific technologies or challenges the team tackles.

3. Connect to mission

Tie your interest to Brex's mission of empowering businesses financially, showing you care about the impact of your work.

4. Articulate long-term vision

Describe a realistic growth path within Brex, such as deepening technical expertise, leading projects, or moving into engineering leadership.

5. Emphasize growth mindset

Highlight your desire to continuously learn and adapt, and how Brex's environment supports that development.

Key Points to Mention

  • Brex's mission to empower businesses financially
  • Specific Brex products or recent innovations (e.g., Brex Card, Brex Cash)
  • Alignment of your technical skills with Brex's tech stack or engineering challenges
  • Opportunities for growth within Brex, such as mentorship or leadership paths
  • Your long-term goal to contribute to Brex's success while advancing your career
  • Brex's company culture and values, and how they resonate with you

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.