[PAISEH]
Engineer AI systems, not model calls.
A principal-level handbook for designing, building, evaluating, deploying, operating, and improving reliable AI systems.
Principal means principal-engineer depth: system boundaries, tradeoffs, review gates, operational ownership, and production judgment.
PAI-SEH Method
One system for reading, designing, and reviewing AI systems
Book Lifecycle
The production AI lifecycle
Discover
Identify whether AI belongs in the problem, define the system’s purpose, and map the risks before design begins.
01Foundations of AI Systems Engineering
Define the discipline, explain why AI systems differ from deterministic software, and establish the language used throughout the handbook.
03Requirements, Risk, and Product Fit
Translate user needs into AI-appropriate requirements, decide whether AI is justified, and identify the blast radius before implementation.
Design
Shape the system architecture, control boundaries, context strategy, prompt contract, and governance model.
02The AI System Stack
Introduce the architecture model that connects business problem, engineering problem, evaluation, harness, context, prompt, model, and infrastructure.
04Prompt Engineering for Production
Move beyond prompt tricks into durable instruction design, prompt contracts, examples, structured outputs, and prompt change management.
05Context Engineering and Retrieval
Design the data, retrieval, ranking, memory, compression, and authorization layer that makes AI behavior grounded and useful.
06Harness Engineering and Control Loops
Build the operating layer around the model: routing, retries, validation, fallbacks, state transitions, approvals, and traceability.
09Security, Privacy, and Governance
Address prompt injection, data leakage, model and supply-chain risk, privacy boundaries, compliance, retention, and responsible AI review.
Develop
Connect models to tools, workflows, deployment paths, and reference architectures that can be built and reviewed by engineering teams.
07Tool Use and Agentic Workflows
Safely connect AI systems to tools, APIs, files, databases, workflows, and long-running tasks without losing control of authority.
10Deployment and Runtime Architecture
Package, deploy, version, route, scale, and roll back AI systems across model versions, prompts, retrieval indexes, tools, and policies.
12Reference Architectures and Design Reviews
Compare common patterns including RAG, copilots, workflow agents, AI search, human-in-the-loop systems, and hybrid architectures.
Evaluate
Turn quality, safety, and release readiness into an engineering system rather than a subjective judgment.
08Evaluation Engineering
Create the quality system for AI: scenario suites, golden datasets, adversarial tests, human review, production sampling, and release gates.
Operate & Improve
Run AI systems in production, learn from failures, and improve the product through traces, incidents, case studies, and reusable runbooks.
11Observability, Incidents, and AI SRE
Operate AI systems using traces, logs, semantic quality signals, cost telemetry, drift monitoring, incident response, and continuous improvement.
13Case Studies
Walk through realistic systems such as customer support, enterprise search, document intelligence, financial copilots, coding assistants, and operations agents.
14Templates, Checklists, and Runbooks
Provide reusable operating assets that teams can copy into real projects and adapt for their own review process.
Core Disciplines
The engineering disciplines used throughout the handbook
Prompt Engineering
Design maintainable instructions, output contracts, examples, constraints, refusal behavior, and prompt versioning.
- What must the model optimize for?
- What should it never do?
- How is prompt behavior tested?
Context Engineering
Build the system that selects, ranks, compresses, authorizes, and refreshes the information given to the model.
- Which sources are trusted?
- How fresh must context be?
- What happens when context is missing?
Harness Engineering
Create the control layer around the model: orchestration, validation, retries, state, guardrails, fallbacks, and recovery.
- What controls model behavior?
- Where do we validate output?
- How does the system recover?
Evaluation Engineering
Turn quality into an engineering system through golden tasks, adversarial cases, human rubrics, regression suites, and online signals.
- What does good mean?
- What failures are unacceptable?
- What blocks release?
Agent and System Architecture
Design single-agent, multi-agent, workflow, human-in-the-loop, and event-driven systems with explicit responsibility boundaries.
- Who owns each decision?
- When does the system ask for help?
- How is long-running work supervised?
Signature Framework
The design review before an AI system gains power.
A principal-level review sequence for expanding autonomy, adding tools, exposing users, or increasing production risk.
Open framework- Define the business problem, engineering problem, and why AI is the right mechanism.
- Draw the system boundary across user intent, context, model, tools, state, policy, review, and observability.
- Name the decision surface: what the AI may recommend, draft, decide, execute, or refuse.
- Map the blast radius across quality, security, privacy, reliability, cost, latency, and trust.
- Set the release gate: eval thresholds, human review, fallback behavior, rollback, and production monitoring.
Reusable Assets
Templates for real engineering reviews and operations
AI System Design Doc
- Problem and non-goals
- System boundary
- Context sources
- Tool permissions
- Eval plan
Launch Readiness Review
- Quality threshold
- Risk acceptance
- Fallback behavior
- Owner sign-off
- Rollback path
Evaluation Plan
- Golden tasks
- Adversarial tests
- Human rubric
- Regression suite
- Production sampling
Incident Runbook
- Detection signal
- Triage path
- Containment
- User communication
- Post-incident review
Release Scorecard
Five questions before production launch
Problem Fit
AI is justified by ambiguity, scale, personalization, or reasoning need, not novelty.
Boundaries
Inputs, outputs, tool authority, data access, and human approvals are explicit.
Grounding
Sources are trusted, fresh enough, permission-aware, and handled honestly when unavailable.
Evaluation
Release decisions use scenario evals, adversarial cases, human review, and production traces.
Operations
The system can be traced, rolled back, monitored, costed, and improved after launch.