Courses / Foundations of Forward Deployed Engineering / Your first AI feature

Lesson 26 of 35 · PremiumCourse syllabus

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1. The role

Connect a software capability to a working customer workflow25 min · Free
Compare engineering roles by actual ownership, not the title25 min · Free
Run the engagement as a learning loop with explicit release gates28 min · Free

2. Discovery

Test the stated request against the work people actually do28 min · Free
Map the people, decisions and prerequisites behind the pilot25 min · Free
Write a scope that can be tested, approved and changed deliberately30 min · Free
Lab: turn a customer's request into a pilot you can actually judge90 min · Premium

3. Reading systems

Build an evidence map of an unfamiliar system28 min · Free
Specify the ownership, trust, network and meaning at each boundary28 min · Free
Test replay, slow dependencies and changing data before adding load30 min · Free

4. Code that survives in someone else's system

Translate source data without losing its meaning30 min · Free
Choose retries from outcome evidence and a time budget30 min · Free with sign-in
Leave tests that catch regressions and explain their limits30 min · Free with sign-in

5. Data that fights back

Profile the data and turn uncertainty into a scoped plan28 min · Free with sign-in
Make replays safe without overwriting newer facts30 min · Free with sign-in
Investigate undocumented behavior with bounded evidence28 min · Free with sign-in
Lab: assemble a pipeline and reconcile every replay150 min · Free with sign-in

6. Modelling their world

Resolve identities without hiding uncertain or unmatched records30 min · Free with sign-in
Declare the grain and prove that the totals survive joins30 min · Free with sign-in
Preserve valid history and the history of what you knew30 min · Premium

7. The proof of concept

Give the proof of concept a decision and an evidence standard28 min · Free with sign-in
Use prototype shortcuts without changing the claim unnoticed28 min · Free with sign-in
Put the prototype in users’ hands with a bounded access plan28 min · Free with sign-in

8. Your first AI feature

Trace the evidence before changing the prompt22 min · Premium
Write the evaluation before the feature, or you will never know if it works25 min · Premium
Design for being wrong, because the system will be wrong in front of the customer24 min · Premium
Project: repair a streaming assistant and prove which run owns each write120 min · Free with sign-in

9. Operating what you shipped

Validate configuration before serving and make credential changes testable30 min · Free with sign-in
Connect operational signals to outcomes and expose missing evidence30 min · Premium
Define service levels with explicit denominators and a usable response policy30 min · Premium

10. Saying it

Lead an update with the decision and keep its evidence intact28 min · Premium
Demonstrate a customer workflow with visible evidence and honest limits28 min · Premium
Transfer operational capability with evidence, rehearsal and accepted ownership30 min · Premium

11. Capstone

Capstone: build one engagement file from evidence through operational transfer360 min · Premium
Lab: defend your engagement when the requirements change90 min · Premium

Design for being wrong, because the system will be wrong in front of the customer

Design the response to an error alongside the answer itself. Validate supporting evidence, distinguish abstention from access denial, and size the human review path before promising it. Citations and confidence scores alone do not establish correctness.

24 MIN · PREMIUM

By FDEInterviews · Updated Oct 23, 2026

The mental model interviewers reward starts one level deeper than the definition: what the concept buys you, what it costs, and the single trade-off that decides when to reach for it.

Work the concrete example end to end, then name the failure mode most candidates miss — that is the signal that you have used this in production, not just read about it.

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Read the related research

See all 13 related papers →

Free summaries. Key takeaways with a free account; deeper analysis with Premium.

2023 · 11 min breakdownGrammar-Constrained DecodingThe 2023 EPFL paper showing that masking a model's tokens with a grammar guarantees the output's shape, lifts accuracy without training, and has a trap: valid but empty.Read the summary →
2023 · 11 min breakdownSGLangA serving system for programs that call a model many times: it caches KV across requests in a radix tree, decodes fixed JSON text in one step, and ran agent workloads up to 6.4× faster.Read the summary →
2025 · 13 min breakdownAgentSpecWrite safety rules as trigger, check and enforce, and run them before every agent step. Hand-written rules stopped most risky actions in milliseconds; rules written by an LLM were patchier.Read the summary →

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The Forward Deployed Engineer Case Rounds →

A worked case or conversation in the Case Rounds book points here. Run the round under its clock, score the recording, then return to this page to check the reasoning. Three sample pages are free to preview.

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The Forward Deployed Engineer Take-Home Playbook →

A practice project in the playbook points here. Do the project under its time budget, then return to this page to check the reasoning. Three sample pages are free to preview.