Most Forward Deployed Engineer interviews are really two interviews stitched together.
A technical round to check they can code, and a “customer” round to check they can hold a conversation.
Candidates who pass both still fail in the role surprisingly often, because the thing that makes an FDE great lives in the gap between those two rounds.
It shows up in how someone thinks when the problem is messy, the customer is unclear and nobody has written the ticket yet.
This blog covers the signals worth looking for, and how to design an interview that actually surfaces them.
Why standard Engineering interviews miss the point
A strong Software Engineer and a strong FDE can look identical on paper. Same languages, same years of experience, similar projects.
The difference is the environment they do their best work in.
A Product Engineer is usually handed a reasonably well-defined problem inside a codebase they know. An FDE is dropped into a customer’s world, often with partial access, unfamiliar data and a stakeholder who can describe the pain but not the fix. Their job is to turn that into something working, quickly, and to feed what they learn back to the product team.
So if the interview only asks “can this person solve a defined problem well?”, it’s testing the wrong half of the job. The more useful question is: what does this person do when the problem isn’t defined at all?
Signal One: Curiosity that goes past the brief
Great FDEs ask a lot of questions, and they ask them early.
Not filler questions to look engaged. Real ones. Who uses this? What happens today when it breaks? Why does the customer think this is the priority? What does success look like in three months?
A simple way to test this is to open a scenario round with deliberately thin information. Something like: “A customer says our integration is too slow. Over to you.” Weaker candidates start designing a solution straight away. Stronger ones spend the first ten minutes working out what “too slow” means, for whom, and whether it’s even the real problem.
Listen for the moment they reframe the question. That’s usually the moment you’ve found someone good.
Signal Two: A bias to action, without recklessness
Curiosity on its own isn’t enough. Some candidates will happily ask questions for an hour and never commit to anything.
The FDE role rewards people who can get to a sensible first step fast, ship something small, and learn from what happens. In customer environments, a working prototype on day three is often worth more than a perfect design on day thirty.
Ask candidates to talk you through a time they had to move before they had all the information. What did they choose to do first? What did they decide was safe to leave for later? What would they do differently?
The good answers have a clear shape. They name the risk, explain why they accepted it, and describe how they’d have backed out if it went wrong. That balance is exactly what you want in front of an enterprise customer.
Signal Three: The ability to simplify
FDEs spend a lot of time translating. Technical detail for a non-technical buyer. Customer frustration for a product manager. A sprawling set of requirements into a scope someone can actually deliver.
You can test this directly. Ask a candidate to explain a technical decision from their past work twice: once as they’d explain it to a fellow Engineer, and once as they’d explain it to a head of operations who has five minutes and no interest in the stack.
Strong candidates change more than their vocabulary. They change what they lead with. The Engineer hears about the trade-off. The operations lead hears about what it means for their team on Monday morning.
If both explanations sound the same, the candidate may be excellent technically, but they’ll struggle in front of customers.
Signal Four: Comfort with ambiguity and pressure
Some of the best FDE work happens on bad days. A go-live slips, a data feed arrives broken, a senior stakeholder joins the call unexpectedly and wants answers now.
You won’t recreate that perfectly in an interview, but you can get close. Introduce a change halfway through a scenario round. New constraint, new stakeholder, a requirement that contradicts something said earlier. Then watch.
Do they get flustered, or do they acknowledge the change and re-plan out loud? Do they push back where it makes sense? Do they keep the customer’s goal in view, or get lost defending their original approach?
Calm, structured re-planning is one of the most reliable predictors we see of how someone will cope in the field.
Designing a loop that surfaces these signals
None of this needs a longer process. It needs a more deliberate one. A loop that works well for most SaaS teams looks something like this:
A short technical screen focused on practical coding and debugging in a realistic environment, not puzzles.
A scenario round built on a real (anonymised) customer problem, opened with thin information and changed partway through.
A translation exercise where the candidate explains the same decision to two very different audiences.
A conversation with someone customer-facing, such as a solutions engineer or account lead, who can judge whether they’d trust this person in the room.
Agree in advance what “good” looks like for each signal, and score against it. Without that, interviewers default to gut feel, and gut feel tends to favour whoever was most confident rather than most effective.
Red flags worth taking seriously
A few patterns come up again and again in FDE hires that don’t work out:
Candidates who treat the customer as an obstacle to the “real” engineering work.
Candidates who can only describe their impact in technical terms, never in terms of what changed for the user or the business.
Candidates who never ask a single question in the scenario round.
Any one of these on its own might be nerves. Two or more is usually a pattern.
Hiring for the gap, not the halves
The best Forward Deployed Engineers are not simply good Engineers who are also good with people. They’re people who are energised by ambiguity, curious about how customers actually work, and quick to turn that understanding into something real.
Build your interview around that gap, and the right candidates become much easier to spot. Build it around the two halves, and you’ll keep hiring people who look right and struggle once they’re in front of a customer.
If you’re building out an FDE team and want a second pair of eyes on your interview loop, the Runtime team is always happy to talk it through.
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