FDE vs sales engineer: where the roles split
Updated
Demos that sell versus systems that stay: the handoff between presales craft and delivery ownership.
Both roles demo. Only one of them gets paged afterwards, and that changes everything about how each demo is built.
The short answer
Sales engineers prove value before the signature with demos. FDEs prove it after the signature with a running system, metrics and a handover package.
The decision table
| Axis | Sales engineer | Forward deployed engineer |
|---|---|---|
| Demo data | Curated fixtures | Live customer data, then fixtures for tests |
| After signature | Moves to next deal | Stays for the whole loop |
| Code standard | Throwaway-allowed prototype | Production code with tests |
| Constraint handling | Acknowledged in slides | Survived in security review and windows |
| Measured by | Pipeline and wins | Outcome metric plus renewal |
Worked example: the demo that became a system
A fictional sales engineer (fictional) demos returns lookup on fixtures in 20 minutes and wins the pilot. The FDE inherits the demo, discovers the real pain is duplicate quarantine, ships the rule table and error report, and hands over the runbook. Same story, two crafts: one opens the door, the other makes Tuesday shorter. The FDE skills guide lists both crafts; the readout post shows how delivery converts to renewal.
Checklist: which craft
- You love new accounts every month: presales. You love one customer for a quarter: FDE.
- Throwaway prototypes delight you: presales. Runbooks strangers can run delight you: FDE.
- You measure in pipeline: presales. You measure in recovered hours: FDE.
Related reading
Straight answers
Frequently asked questions
Is an FDE a presales role?
No. FDEs join discovery and demos, but they stay for build, ship, operate and handover. Presales hands over after signature.
Do sales engineers code?
They build demos and prototypes that prove value fast. FDEs build production systems with tests, rollback and runbooks.
Which one should I pick?
Pick presales if you love the deal cycle and breadth across accounts. Pick FDE if you want to own one customer outcome to handover.