Forward deployed engineer interview questions
180 questions across 10 rounds, each with a framework for answering it and a model answer.
Recruiter screen
Motivation and fit: why this role, why this company, and what you expect from it. Short answers in your own words.
- Give me your background in about a minute, ending with why this role.
- This role involves travel to customer sites. What can you commit to, and what would make it unworkable?
- What are your compensation expectations?
- What customer-facing experience do you have? Be specific about who the customer was.
- Why forward deployed engineering, and not a software engineering role?
- Why this company, and why now?
- What level do you think you are, and why?
- Tell me about the fastest-moving environment you have worked in. What did you like and dislike?
- What kind of problem are you most excited to spend the next two years on?
- Where else are you interviewing, and how far along are you?
Hiring manager
Your own projects, told in the first person: the decisions that were yours, what you traded away and what happened next.
- Looking at your take-home submission, what would you change with another day, and what did you leave out on purpose?
- Pick a project you are proud of. Which decisions were yours alone, and which would have happened without you?
- Pick one project from your résumé and take me through it in depth: the problem, your design, what broke and what you would change.
- Describe your current role in depth: what you own, how your team is organized and how your work reaches customers.
- How do you use AI coding tools in your daily work, and where do you not trust them?
- If I called the last customer you worked with, what would they say you did well and what would they say you missed?
- If you joined and were placed with a new customer next week, what would your first month look like?
- What is the hardest technical problem you have solved? Take me into the details.
- When a customer brings you a vague problem, what do you do in the first week?
- Your résumé mentions a data pipeline you built. Walk me through its failure modes and how you monitored it.
Coding
Practical code you narrate as you write it: parsing messy input, limits and retries, tests you can run, and the edge cases you name first.
- Parse a CSV export with inconsistent dates, stray quotes and repeated header rows into clean records, and report what you dropped.
- Parse web server logs and report the slowest endpoints by p95 latency.
- Write a retry wrapper with exponential backoff and full jitter. Which errors should it not retry?
- Build retrieval over a folder of text files using TF-IDF with no external libraries. Return the top passages with scores.
- Here is a long function that reads files, calls an API and writes a report. Refactor it so you can test it.
- Implement a per-user token bucket rate limiter. Then make it work across several processes.
- Implement a sliding-window rate limiter and explain its memory cost.
- Before you write code for this parser, list the inputs that will break it.
- Build a small CLI with subcommands to import, validate and export records. How do you structure it?
- Compare two exports of the same table and report added, removed and changed rows.
Enterprise system design
Designs that run inside a customer’s environment: a walking skeleton first, then identity, trust boundaries, data movement and rollback.
- Design a bulk import service that validates customer spreadsheets and explains every rejected row.
- Design how your product authenticates a large customer’s employees through their identity provider and removes access the day someone leaves.
- Design prompt versioning and rollback for a system with dozens of prompts used across several customers.
- Design a data platform that unifies a retailer’s point-of-sale, e-commerce, loyalty and supplier feeds into one customer and product view.
- Design a retrieval assistant over a state court system’s procedure manuals, deployed inside the court’s own cloud tenancy, with no case records leaving it.
- Design an evaluation harness that runs before every change to a customer-facing support agent.
Decomposition
A vague customer problem to scope: clarify before solving, name the stakeholders and the data, then sequence the work by risk.
- A city transit agency says its buses are unreliable and riders are leaving. You have a week with their team. How do you approach it?
- A grocery chain wants shorter checkout lines without hiring more staff. How do you approach it?
- A regional food bank says donated food spoils before it reaches families. Decompose the problem.
- A bank wants to approve small-business loans faster without taking more risk. How would you break this down?
- A hospital group wants fewer patients readmitted soon after discharge. Where do you start?
- A manufacturer says unplanned downtime is killing its margins. They have sensor data nobody uses. What do you do?
- Here is a table of events from a fitness app. Pick one feature to build from it and scope it to something you could ship in two weeks.
Client simulation
Conversations with a difficult customer: diagnosis before solutions, options with their trade-offs, and commitments you can keep.
- A non-technical VP asks why the assistant cannot be right every time. Explain in two minutes.
- Procurement asks you, the engineer, to confirm in writing that the deployment will need no more than two of your engineers for a year. Respond.
- Tell the customer’s CTO that the integration will land three weeks late. Your account executive promised her this date.
- The customer’s product manager adds a new dashboard request on every weekly call, and the core pipeline is not done. Handle this week’s call.
- The customer’s security lead will not grant production credentials for another month. Your launch is in two weeks. What do you say to him?
- Write a reply to a customer email demanding a full rollout to every user by Monday, with features you have not built.
- The customer’s chief architect insists on building the agent on their in-house framework, which you think will fail. Respond.
Behavioral
Stories from your own work, owned in the first person and short enough to leave room for follow-ups.
- Tell me about a project you owned from the first customer conversation to production. Which decisions were yours alone?
- Tell me about a time you worked inside a customer’s environment rather than your own. What was hardest?
- Describe a stakeholder who was quietly working against your project. What did you do before you escalated?
- Tell me about a decision you made that turned out to be wrong. How did you find out, and how fast did you reverse it?
- Tell me about a failure that was your fault. What did it cost, and what do you do differently now?
- Tell me about a time you said no to a customer or senior stakeholder. What did the relationship look like a month later?
- FDE work can mean travel and constant context switching. Tell me how you have handled a sustained period of heavy load.
- Tell me about a time a user or customer showed you something that changed your mind about a technical approach.
- Tell me about a time you automated away work you used to do by hand for a customer.
- Tell me about a time you had to become useful in an unfamiliar domain within a couple of weeks. How did you learn it?
AI systems and evaluation
For AI rolesBuilding with models in production: retrieval, agents, guardrails, and above all how you prove the system works.
- A customer asks how you know your AI system works. Answer them.
- How do you choose a chunking strategy for contracts compared with support tickets?
- How do you make an assistant cite its sources, and how do you check the citations are real?
- Retrieval finds the right document in the top twenty but not the top three. What do you do?
- When would you fine-tune, when would you use retrieval, and when is prompting enough? Use a real example.
- A support agent reads customer emails and can issue refunds. How do you defend it against prompt injection?
Reliability and operations
Keeping a deployment running: failure modes, observability, incidents, capacity and safe changes in someone else’s environment.
- A customer reports that some requests to your API fail, and you have logs and nothing else. Walk through your first hour.
- A customer’s payment webhook was processed twice. Design the fix.
- A downstream service recovers from an outage and immediately falls over again. Why, and how do you prevent it?
- Define service level objectives for an AI assistant a customer depends on. What do you measure?
- How do you roll out a risky change to a system running in a customer’s environment?
SQL and data
Queries against realistic data: joins that multiply rows, windows, deduplication, and checking the answer before you trust it.
- After a join was added, revenue came out far too high. Find and fix the fan-out.
- For each ticket, return only its most recent status.
- Write a running total of revenue per customer by day.
- Compute the monthly return rate by first-purchase cohort.
- Group page views into sessions separated by a period of inactivity.
- This query got slow after the table grew. Read the plan and say what you would change.
Questions with a company source
Where a published statement or a candidate report names a company and the round, the question carries a tag that says which it is. What each company publishes about its hiring, and what candidates report, is in the company guides.