Chapter 02Foundations6 min read

The eight FDE archetypes

What you’ll learn

Eight distinct archetypes (AI labs, data labs, horizontal apps, vertical agents, enterprise SaaS, regulated verticals, dev tools, defense), each with its own customer interface, travel intensity, and comp band.

A

AI lab / foundation model companies

e.g. OpenAI, Anthropic, Google DeepMind, Mistral, Cohere, xAI

Job to be done
Turn raw model APIs into production deployments at Fortune 500 / government accounts. Own discovery, eval design, system build, rollout. Increasingly: build agentic systems.
Tech depth
Full SWE + LLM application expertise. Python, TypeScript, prompt engineering, agent development, evals.
Travel intensity
Hybrid 3 days/week + 25–50% travel.
Day-to-day mix
40–50% coding, 20–30% customer discovery, 15–20% internal product feedback.

Concrete example

OpenAI + Morgan Stanley: 98% advisor adoption.
OpenAI + Klarna: 400+ policies parameterized.
Mistral + Ericsson: Codestral fine-tune for legacy code translation.
B

Data lab / RLHF / talent platform companies

e.g. Scale AI, Surge AI, Mercor, Turing, Invisible

Job to be done
Build data pipelines, RL environments, and eval harnesses for AI labs as customers. Less ‘enterprise deployment,’ more ‘embedded with research customers.’
Tech depth
ML researchers and ML platform engineers at AI labs (less C-suite than segment A).
Travel intensity
Mostly hybrid SF/NY. Customer base is concentrated, so less travel.
Day-to-day mix
~60% coding (data pipelines, eval infra), ~20% customer collaboration, ~20% internal platform.

Concrete example

Note on market shift:Meta's mid-2025 ~$14.8B partial acquisition of Scale (Alexandr Wang to Meta) put many Scale alumni into circulation, they are an active sourcing pool through 2026.
C1

Horizontal application platforms

e.g. Glean, Cursor, Cognition

Job to be done
Build the ‘last mile’ of the deployment into the customer environment, bespoke connectors, agents, workflows. Glean’s ‘Founding FDE’ posting is unusually founder-flavored: ‘Your primary job is 0-to-1 product creation … What you build becomes what Glean ships.’
Tech depth
Heavy full-stack. Cursor: ‘Strong in Python and TypeScript/JavaScript … handled production reliability before (metrics, alerts, incident response).’ 5+ years typical.
Travel intensity
Mostly remote/hybrid. Cursor explicitly remote-friendly.
Day-to-day mix
Heaviest coding share of any segment. Less travel; deep customer integration work.
C2

Vertical agent companies

e.g. Sierra, Decagon, Harvey, Hebbia

Job to be done
Configure / build agents for specific customer workflows on the customer’s platform. Less ‘novel system design,’ more ‘agent design + integration + evals.’ Sierra’s deliverable is a working agent with guardrails on Agent OS, more configuration than custom-app builder.
Tech depth
Full-stack. Hebbia: 5+ years at venture-backed startup or top tech firm; APIs, data pipelines, frontend when needed.
Travel intensity
High in-office. Hebbia: 5 days a week in NYC/SF, embedded onsite with major buyside customers. Sierra: in-person SF.
Day-to-day mix
~40% coding, 30–40% customer scoping/agent design, 20% feedback to product. Heavier on AOPs (agent operating procedures), agent skills, and guardrail design than novel infrastructure building.
D

Enterprise SaaS / B2B horizontal adopters

e.g. Ramp, Salesforce, Rippling, Sourcegraph

Job to be done
Make complex enterprise SaaS work for biggest customers; integration depth into their data/systems; close enterprise deals.
Tech depth
Full SWE, with rising LLM literacy. Less RLHF/fine-tune than AI labs.
Travel intensity
Ramp runs ~16 FDEs in pods, 7 of whom are former founders (Leo Mehr, Ramp Builders, August 5, 2025). Salesforce launched Agentforce FDE program April 2025: pods of 1 deployment strategist + 2 FDEs, full-time on one client for ~3 months (‘Momentum’ program). Sourcegraph requires 80% travel Mon–Thu for onsite customer engagements.
Day-to-day mix
~50% travel including travel / on-site requirements.
E

Vertical AI in regulated industries

e.g. Harvey (legal), Hebbia (finance), OpenAI Life Sciences/Federal, Anthropic Federal Civilian, Commure (healthcare), Chestnut (insurance)

Job to be done
Regulatory and compliance constraints define the role. OpenAI Life Sciences FDE: ‘Define launch criteria for regulated contexts, including validation evidence, outcome metrics, and acceptance thresholds tied to production use.’ Enforce operating standards for auditability, traceability, and inspection-readiness.
Tech depth
Full SWE + domain depth + validation rigor. Eval design and acceptance criteria are first-class deliverables.
Travel intensity
25–50%, often onsite extensively. Commure ~50%.
Day-to-day mix
Heavy compliance work. Eval suites, validation evidence, inspection readiness.
F

Agentic startups (overlaps with C2)

e.g. Sierra a/b/iSpec, Decagon, Harvey, Vircel

Job to be done
The ‘FDE’ is increasingly an ‘Agent Engineer’ or ‘Agent PM’ whose deliverable is a working agent (with goals, guardrails, evals, AOPs) rather than a custom application. Sierra explicitly refuses the FDE label and uses ‘Agent Engineer’ (sierra.ai/blog, December 2024). a16z calls this ‘title arbitrage’: legal engineer, GTM engineer, agent engineer, all denoting ‘AI made this work different.’
Tech depth
Full-stack engineers doing significant agent-tuning, evals, and guardrail work, different shape than research-heavy AI labs.
Travel intensity
Mostly hybrid SF/NY.
Day-to-day mix
Heavy on agent design, less on traditional integration.
G

Dev tools / DevEx companies

e.g. Cursor, Sourcegraph, Cognition, Replit, Vercel

Job to be done
The customer is itself an engineering team, so the FDE is an engineer-to-engineer rather than enterprise consultant. Cursor’s posting: ‘work directly with Staff/Platform/Eng leaders, going deep in code while also communicating clearly about tradeoffs.’ Workflows shipped: large-scale refactors, migration tooling, PR review loops, internal codemod platforms.
Tech depth
Strong production engineering. Production codebases included.
Travel intensity
Mostly remote/hybrid. Less customer travel than enterprise FDEs.
Day-to-day mix
Engineer-to-engineer; deep code work.
H

Defense / government tech

e.g. Palantir (FDE - original), Anduril (Mission Operations Engineer / Mission Software Engineer), Shield AI, Helsing

Job to be done
Embedded with military, intel, and government customers, often in austere or air-gapped environments. Palantir’s ‘Forward Deployed Software Engineer’ frames the role as ‘hands-on AI startup CTO.’ Anduril’s MOE: up to 75% travel to forward-deployed accounts, active US clearance often required.
Tech depth
Production engineering with security clearance background.
Travel intensity
Highest of all segments. Defense/gov roles add SERE training, ISOPREP, foreign-travel pre-clearance. ISOPREP, Antiterrorism Level I, APACS clearance per DoD 4500.54E. Foreign travel may require months of pre-clearance. Fully cleared FDEs are ‘the unicorns of the unicorns.’
Day-to-day mix
Field embedding > coding share.

Cross-segment quick reference

Use this table as a decision tool when scoping a search.

What an FDE looks like across segments
Archetype% codingTravelMid-senior TCDistinct artifact
A. AI Labs40–50%25–50%$350–550KEvals, agents, MCP servers
B. Data Lab~60%Low$180–280KEval pipelines, RL envs
C1. Horizontal App50–60%Remote / hybrid$200–400KNew product surfaces
C2. Vertical Agent~40%High in-office$200–350KAOPs, agent skills, guardrails
D. Enterprise SaaS30–40%Variable, up to 80%$180–300KCustom integrations
E. Regulated35–45%25–50%$250–450KValidation evidence
G. Dev Tools60%+Low$200–400KWorkflow automations
H. Defense30–40%25–75%$135–200K base + RSUMission ontology

Key takeaways

  • Pick the archetype before you write the JD. Mismatching is the single most expensive failure mode in FDE recruiting.
  • Coding share, travel, and comp differ by 2–3× across archetypes. A Palantir FDE and a Sierra Agent Engineer share a job title and almost nothing else.
  • Defense / gov FDEs are “the unicorns of the unicorns.” Clearance eligibility is a hard pre-screen, not a nice-to-have.