The Role
Chapter 1: The New Field Engineer
- The Production Gap That Created a Profession
- What a Forward Deployed Engineer Actually Does
- From Palantir Curiosity to Industry Standard
- Why AI Makes Field Engineering Essential
- FDE vs Everything Else
- Real Engineering or Fancy Consulting?
- The Pod and the FDE
- Do You Need an FDE?
- The Harness Engineering Connection
- The FDE Mindset
- Field Exercise
- Key Takeaways
Chapter 2: The Honest Career
- Why Engineers Are Interested Now
- Will This Keep Me Technical?
- A Realistic Week
- Career Paths
- Compensation
- The Interview
- Positioning Your Application
- Burnout, Travel, and Red Flags
- Negotiating the Offer
- Field Exercise
- Key Takeaways
Chapter 3: The Capability Model
- The T-Shaped Field Engineer
- The Five Capability Families
- The Maturity Model
- The Minimum Viable Technical Stack
- The Learning Path
- Field Exercise
- Key Takeaways
The Method
Chapter 4: Discovery in the Real World
- The Gravel Track
- The First Week Determines Everything
- Three Lenses, Not Three Phases
- Preparing for the First Week
- The Five-Day Discovery Protocol
- Stakeholder Interviews
- The Discovery Output
- Field Exercise
- Key Takeaways
Chapter 5: Discovering the Work
- Two Processes
- The Prototype Is the Instrument
- The Process Is Already Written Down, in the ERP
- Choosing the Unit of Work
- Watching People Work
- The Process Specification
- Exception Archaeology
- Deciding What the Agent Does
- Measuring the Baseline Before You Change It
- Validating the Specification
- Field Exercise
- Key Takeaways
Chapter 6: Discovering What People Know
- Four Seconds
- Four Kinds of Knowledge
- Why Interviews Fail
- Elicitation
- Writing Knowledge Down
- The Data Half
- Bias, and What You Are Encoding
- What Not to Capture
- Knowing Whether It Worked
- Field Exercise
- Key Takeaways
Chapter 7: Discovering the Tools of the Job
- Eleven Applications
- Inventory From the Desk Outward
- The Tool Inventory
- The Interface Ladder
- From Tools to Actions
- Who Is the Agent?
- Observability and Somewhere to Fail
- Feasibility, and the Honest Report
- Field Exercise
- Key Takeaways
Chapter 8: From Ambiguity to Executable Plans
- The Translation Problem
- Writing Outcome Statements
- From Outcome to Plan
- Choosing the Right Delivery Vehicle
- Managing Scope Without Losing Momentum
- Demo-Driven Development Without Demo Theatre
- Writing Plans That Both Sides Trust
- Field Exercise
- Key Takeaways
Production
Chapter 9: AI Patterns for Field Engineers
- Start by Not Using AI
- The Building Blocks
- Agent Patterns in Practice
- Context Engineering
- RAG: When It Helps and When It Distracts
- Tool Use and MCP Servers
- Keeping Architecture Simple Enough to Ship
- Field Exercise
- Key Takeaways
Chapter 10: Data, Integration, and Customer Systems
- The Job Is Integration
- Integration Patterns
- Structured, Semi-Structured, and Unstructured Data
- Data Access, Identity, and Least Privilege
- Source-of-Truth Problems
- MCP: The Integration Standard
- The Smallest Useful Vertical Slice
- The Last Mile
- Field Exercise
- Key Takeaways
Chapter 11: Evaluation and Harness Engineering
- The Model Is Not the Product
- The Six Harness Layers
- The Ratchet Principle
- Eval-Driven Development: The OpenAI FDE Method
- The Counter-Intuitive Testing Result
- Evaluation Infrastructure
- Harness Maturity Levels
- Building Harnesses That Survive the Engagement
- Field Exercise
- Key Takeaways
Chapter 12: Production, Security, and Governance
- Why Demos Lie
- Production Readiness: Six Dimensions
- The AI Threat Model
- Harness Security: Engineering, Not Hope
- CI/CD for AI Systems
- Incident Response for AI
- The EU AI Act: What FDEs Must Know
- Performance, Cost, and Token Accounting
- Field Exercise: The Production Readiness Review
- Key Takeaways
The Human Side
Chapter 13: Working with Customers
- The Order-Taker Trap
- The Trust Spectrum
- Explaining AI Limitations Without Undermining Confidence
- Handling Sceptics and Champions
- Negotiating Trade-Offs
- Making Invisible Progress Visible
- Field Survival
- The “Permanent Crutch” Anti-Pattern
- Field Exercise: The Weekly Field Update
- Key Takeaways
Chapter 14: Adoption, Handover, and Product Feedback
- The FDE’s Real Deliverable
- The Autonomy Ladder
- Training by Doing, Not by Telling
- The Agentic Pod
- Handover Milestones
- Documentation That Survives
- The N-to-1-to-N Lifecycle
- Separating Customer-Specific from Reusable
- The Field Report
- The Harness as Ultimate Handover Artefact
- Field Exercise: The Handover Plan
- Key Takeaways
Chapter 15: Leading and Scaling the Practice
- The View from Above
- The Consulting Trap
- The FDE Lead Role
- Staffing Model
- Quality Standards for Field Deliverables
- Career Paths
- Portfolio Visibility
- Building Reusable Harness Components
- A Complete End-to-End Scenario: Project Atlas
- Hiring in a Candidate-Driven Market
- Field Exercise: The Hiring Rubric
- Key Takeaways
Field-Ready Python
Chapter 16: Modern Python Idioms
- Learning Objectives
- Prerequisites
- What transfers, and what will surprise you
- The data model: the protocols behind the syntax
- Idioms that read as senior
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 17: Typing and Data Modelling
- Learning Objectives
- Prerequisites
- Typing: the checking the compiler used to do for you
- Modelling data: a dataclass in the core, pydantic at the ports
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 18: Async and Concurrency for Agents
- Learning Objectives
- Prerequisites
- The async model, and when it earns its place
- Running tool calls in parallel
- Deadlines, cancellation, and protecting critical work
- Streaming model output
- Backpressure and concurrency limits
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 19: The Modern Python Toolchain
- Learning Objectives
- Prerequisites
- Environments and dependencies with uv
- Linting and formatting with ruff
- The shape of a project: pyproject.toml
- The API you leave behind
- Configuration that fails fast with pydantic-settings
- Command-line interfaces with typer
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 20: Testing and Reliability
- Learning Objectives
- Prerequisites
- pytest and async tests
- Testing non-determinism: mock at the narrowest boundary
- Property-based testing with Hypothesis
- Reliability: timeouts, retries, and circuit breakers
- Handling errors by recoverability
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 21: FastAPI Services and Integration
- Learning Objectives
- Prerequisites
- Typed endpoints with pydantic
- Streaming agent output over SSE
- Auth, background tasks, and structured logging
- Packaging the service as a starter kit
- Summary
- Review Questions
- Exercises
- Further Reading
Framework-Agnostic Agent Engineering
Chapter 22: The Agent Loop from Scratch
- Learning Objectives
- Prerequisites
- The four primitives
- Writing the loop with no framework
- The same loop across providers
- Hardening the bare loop
- Recognising the loop inside the SDKs
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 23: Tools, Function Calling, and Structured Output
- Learning Objectives
- Prerequisites
- A tool is a typed schema
- One pydantic model, three envelopes
- Strict mode: stop parsing and retrying
- Structured output: shaping the final response
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 24: Context Engineering, RAG, and Retrieval
- Learning Objectives
- Prerequisites
- What enters the context, and why less is more
- Grounding the agent in data: RAG
- Keeping the window from overflowing: compaction and editing
- Remembering across sessions: memory
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 25: Multi-Agent Orchestration
- Learning Objectives
- Prerequisites
- Workflows versus agents, and starting simple
- The five essential primitives
- The patterns in the production runtimes
- Essential versus incidental: the durable model
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 26: MCP: Interop Across Ecosystems
- Learning Objectives
- Prerequisites
- The architecture: hosts, clients, and servers
- The three primitives, by who controls them
- Authoring a server
- Consuming across clients and SDKs
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 27: Evaluation, Observability, and Guardrails
- Learning Objectives
- Prerequisites
- Evaluation: knowing it works before you ship
- Observability: seeing what it does
- Guardrails: keeping it safe
- Summary
- Review Questions
- Exercises
- Further Reading
Field-Ready TypeScript
Chapter 28: TypeScript for Typed-Language Engineers
- Learning Objectives
- Prerequisites
- The type system, mapped
- zod: pydantic for TypeScript
- The async and module toolchain
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 29: Node and the AI SDKs
- Learning Objectives
- Prerequisites
- Two SDKs, two jobs
- Streaming, mapped from Chapter 18
- Typed tools with zod
- Summary
- Review Questions
- Exercises
- Further Reading
Chapter 30: Next.js Agent Demos
- Learning Objectives
- Prerequisites
- The App Router: server and client
- A streaming agent UI over your FastAPI agent
- Deploying the demo
- Summary
- Review Questions
- Exercises
- Further Reading
Conclusion
- The harness is the job, and the gap is why the role exists
- The primitive outlives the framework
- Types are where you put the pressure
- Non-determinism is an engineering problem, not an excuse
- What you leave behind
- Where to go next