Forward Deployed Engineers (FDEs) occupy an unusual position in software engineering.

They work close to customers, understand messy real world problems, build integrations, debug unfamiliar systems, and turn requirements into working software. Sometimes they need to do all of this before anyone has fully figured out what the problem actually is.

That makes hiring an FDE different from hiring a traditional software engineer.

A candidate might be excellent at solving algorithmic problems but struggle to investigate an unfamiliar codebase, communicate with a frustrated customer, or make sensible technical decisions under uncertainty.

So how should we evaluate someone for this role?

Let's break it down.

1. Understand what an FDE actually does

An FDE is not simply a software engineer who occasionally talks to customers.

Their job often involves moving between several responsibilities:

• Understanding a customer's workflow and identifying the underlying technical problem.
• Building prototypes and production integrations.
• Working with APIs, databases, distributed systems, and external services.
• Debugging problems in environments they did not build.
• Communicating technical tradeoffs to both engineers and nontechnical stakeholders.
• Turning one customer's solution into something reusable when possible.

The exact responsibilities vary by company. An FDE at an AI startup may spend much of their time integrating models into customer workflows, while an FDE at an infrastructure company might focus on deployment, reliability, and system integration.

The common thread is that they must turn ambiguous problems into useful technical outcomes.

2. The problem with relying only on traditional interviews

Traditional interviews aren't inherently bad. Data structures, algorithms, and system design can reveal important capabilities.

The problem is treating performance in these settings as a complete representation of engineering ability.

Consider three candidates.

Candidate A solves algorithmic problems quickly but struggles when debugging an unfamiliar service.

Candidate B writes code more slowly but methodically traces a failing API request, identifies a database issue, and explains the tradeoffs behind the fix.

Candidate C can build the integration but struggles to understand the customer's actual requirements.

Which candidate is the best FDE?

There isn't enough information to decide from these descriptions alone. The answer depends on the role, the complexity of the work, and the candidate's demonstrated abilities across several situations.

That's precisely why a more realistic assessment can be useful.

3. Evaluate the skills that matter on the job

I would focus on five areas.

Problem solving under ambiguity

Give the candidate a realistic problem with incomplete requirements.

For example, a customer wants to synchronize data between two systems, but the expected behavior for duplicate records and failed requests is unclear.

Does the candidate ask clarifying questions? Do they identify assumptions? Can they separate what is known from what needs to be investigated?

The goal isn't to reward guessing. It's to understand how they approach uncertainty.

Debugging unfamiliar systems

Provide a small application with a reproducible bug.

Ask the candidate to investigate it, explain their hypotheses, use the available logs, and identify the root cause.

Pay attention to their process rather than just whether they arrive at the answer. A good engineer should be able to explain why a hypothesis is plausible and what evidence would disprove it.

System integration

Give the candidate an API integration task.

The happy path should be straightforward, but the scenario should also involve practical concerns such as authentication failures, timeouts, retries, rate limits, and malformed responses.

Production engineering is full of these details. A solution that works only when every dependency behaves perfectly is rarely sufficient.

Technical communication

Ask the candidate to explain a technical decision to someone without a deep engineering background.

Can they explain the problem, the available options, the risks, and the reason for their recommendation?

FDEs frequently need to bridge the gap between customer expectations and engineering constraints. Communication is part of the technical work, not an unrelated soft skill.

Judgment and prioritization

Introduce a constraint: the integration must be demonstrated tomorrow, but the production solution needs reliability and security.

What would the candidate implement first? What would they deliberately postpone? What risks would they communicate?

There isn't always one correct answer. The reasoning and recognition of tradeoffs matter.

4. Use a realistic assessment instead of adding more interview rounds

Imagine a 60 minute assessment built around a fictional customer problem.

The candidate receives a small application, a brief customer request, API documentation, and a bug report.

They must clarify the requirements, investigate the problem, implement or propose a solution, test important failure cases, and explain their decisions.

A possible structure is:

• 10 minutes to understand the problem and clarify requirements.
• 20 minutes to investigate the existing system.
• 20 minutes to implement or develop a concrete solution.
• 10 minutes to explain tradeoffs, testing, and remaining risks.

This is only an example. The format should reflect the actual work expected of the role, and candidates should not be expected to complete an unreasonable amount of production work in an hour.

The assessment should also allow candidates to use the same tools they would reasonably use on the job, including AI coding assistants when appropriate. If AI use is permitted, evaluate how the candidate validates generated code and exercises technical judgment.

5. Evaluate evidence, not just impressions

After the assessment, use a consistent rubric.

For example:

The rubric should be defined before evaluating candidates, and the criteria should reflect the actual job.

A single overall score can hide important differences. One candidate might be strong at debugging but need support with communication. Another might communicate exceptionally well but overlook reliability concerns.

Hiring teams should examine the evidence behind each rating, give candidates comparable opportunities to demonstrate their skills, and use human judgment in the final decision.

No assessment can perfectly predict future job performance. Realistic tasks are useful signals, not guarantees.

6. Where AI can help

AI can make the assessment process more consistent and less expensive to administer, particularly when companies need to evaluate many candidates.

It can help generate role specific scenarios, organize assessment evidence, identify missing information, and summarize how a candidate approached a problem.

But automating the decision itself introduces risks.

An AI system can misunderstand a valid solution, reward a particular communication style, or assign unjustified confidence to a weak evaluation. Automated scoring therefore needs validation, clear criteria, and appropriate human oversight.

At Mindfries, we're exploring how AI can support engineering assessments that focus on practical problem solving and structured evidence, rather than relying entirely on conventional interview answers.

The broader question is how to make assessments useful for hiring teams without turning them into another opaque scoring system.

7. A practical checklist for hiring your next FDE

Before designing the interview process, ask yourself:

• Have we identified the actual responsibilities of this FDE role?
• Do our assessments resemble the problems this person will solve?
• Can candidates explain their reasoning and technical tradeoffs?
• Are we evaluating debugging, integration, and communication where relevant?
• Do we use consistent, job related evaluation criteria?
• Can we explain the evidence behind our assessment?
• Do we give candidates a fair opportunity to demonstrate their abilities?
• Does a human make the final hiring decision?

If you can answer these questions confidently, you're already moving toward a more deliberate hiring process.

Final thoughts

Hiring a Forward Deployed Engineer is ultimately about identifying someone who can connect technical execution with real customer problems.

Algorithmic interviews and system design discussions can remain part of the process. They simply shouldn't be expected to reveal everything about how an engineer will perform.

The more closely we align assessments with the work itself, the more useful the resulting evidence can become.

I'm building Mindfries around this broader problem of evaluating engineering skills through realistic tasks and structured evidence. I'd be interested to hear how other engineering teams approach FDE hiring.

If you hire Forward Deployed Engineers, what practical exercise has given you the strongest signal about a candidate's ability?

I'd love to learn from your experiences.

Learn more: https://mindfries.com/blog/how-to-hire-forward-deployed-engineer