FDE vs. Solutions Engineer vs. Sales Engineer
Four job titles, a ton of overlap, and a lot of confused candidates. Here's how these customer-facing engineering roles actually differ — and which one that job posting really means.
Search for customer-facing engineering jobs and you'll drown in near-synonyms: Forward-Deployed Engineer, Solutions Engineer, Sales Engineer, Implementation Engineer, Deployment Engineer, Applied AI Engineer. They overlap heavily, companies use them inconsistently, and the same title can mean different things at different places.
But there are real distinctions worth understanding — especially if you're deciding which roles to target. Let's untangle them.
The one axis that separates them: how much you build
The cleanest way to think about these roles is a spectrum from "mostly sells / explains" to "mostly builds / deploys."
The further right you go, the more of the job is writing real code that ends up in production at the customer.
Sales Engineer (SE) — the "help close the deal" end
A Sales Engineer supports the sales process with technical expertise: running demos, answering technical objections, scoping proof-of-concepts, and reassuring a customer's technical evaluators. They build some — usually demos and POCs — but their primary job is helping revenue happen before the deal closes. Success is measured in deals influenced.
Solutions Engineer — the overloaded middle
"Solutions Engineer" is the most ambiguous title of the bunch. At some companies it's a fancy name for Sales Engineer. At others it's essentially an FDE. In general, a Solutions Engineer designs and sometimes builds the technical solution for a customer, spanning both pre-sale and post-sale. If you see this title, read the responsibilities carefully — the "how much do you build?" question is the tell.
Implementation / Deployment Engineer — the "make it live" end
These roles kick in after the sale: getting the product deployed, integrated, and working in the customer's environment. Heavy on integration and configuration, lighter on the pre-sale persuasion. Very close to the FDE, sometimes indistinguishable.
Forward-Deployed Engineer (FDE) — build + deploy + own the outcome
The FDE sits at the "mostly builds" end, but with a broader mandate than a pure implementation role. An FDE owns the customer's outcome end-to-end: discovery, building custom integrations and features, deploying into production, and feeding learnings back to the core product. It's the most engineering-heavy and the most ownership-heavy of these roles. The Palantir model — and now the AI-startup model — leans hard on this version.
A quick comparison
Roughly how the roles stack up (generalizing — individual companies vary):
- Sales Engineer — pre-sale focus · builds demos/POCs · measured on deals influenced
- Solutions Engineer — pre + post-sale · builds solutions (varies widely) · measured on customer solution fit
- Implementation Engineer — post-sale · builds integrations/config · measured on successful go-lives
- Forward-Deployed Engineer — post-sale, deep build · owns end-to-end outcome · measured on the customer actually succeeding
Which should you target?
If you love building and want your code in production at real customers, aim for FDE, Implementation, or Deployment roles. If you enjoy the persuasion and pre-sale energy more than deep building, Sales Engineer may fit better. And for anything labeled "Solutions Engineer," don't trust the title — read the actual responsibilities and figure out where on the build spectrum it lands.
The good news for engineers: the fastest-growing demand right now — especially at AI companies — is on the build-heavy end. Companies need people who can deploy AI products at the customer and make them actually work. That's the FDE.
Targeting FDE roles?
Start with the free field guide — what the role is, why AI companies are hiring so many, and the 3 traits they screen for. From someone who interviews for it.