Design AI assistants people can trust.

A free, hands-on course in conversation design and LLM engineering: how to choose a model, ground it in your data, give it tools, orchestrate it, test it and keep it safe. Rebuilt for how assistants are actually made in 2026.

  • 24modules
  • 10case studies
  • 5 h 40 minof study time
  • 100+languages (machine translation)
  • Freeno sign-up
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Predictable, but brittle. It only handles what someone anticipated, and the user does the work of speaking its language.

Pick your path

Every module stands on its own, but you probably don’t need all 24 first. Choose a role for a suggested route.

The curriculum

From first principles to production. Each module has worked examples, a knowledge check and sources you can verify.

  1. 01

    Foundations of conversational AI

    What an AI assistant actually is, what makes conversation hard to design, and how to tell whether one is working.

    10 minDesign
  2. 02

    From intents to LLMs

    How machines understand language, from intents and slots to embeddings and large language models, and when each approach still wins.

    14 minDesignCode
  3. 03

    Conversation design for LLM assistants

    Personas, system prompts as design documents, turn design, repair strategies and handoff: the craft that makes an assistant feel considered.

    11 minDesign
  4. 04

    The LLM landscape: choosing a model

    How to choose among proprietary and open models: criteria that matter for assistants, the tiers and routing strategies, and a dated snapshot of the families you will meet.

    14 minDesignCode
  5. 05

    Prompting across different models

    Why a prompt that works on one model fails on another, what actually differs, and how to keep prompts portable, versioned and tested.

    17 minDesignCode
  6. 06

    Retrieval-augmented generation (RAG)

    Ground your assistant in your own content: preparing knowledge, chunking, hybrid search, reranking, citations, evaluation and the failure modes to expect.

    12 minCodeDesign
  7. 07

    Preparing documents for ingestion

    How to write, structure and manage source documents so retrieval works: single-document design, multi-document corpora, metadata, versions, format pitfalls and an ingestion pipeline with tests.

    18 minDesignCodeOps
  8. 08

    Tools, function calling and MCP

    Let an assistant act: how tool calling works, how to design tools models can use safely, and what the July 2026 stateless MCP specification changes.

    16 minCodeDesign
  9. 09

    Orchestration: state machines, agents and multi-agent systems

    Choose the right architecture: deterministic flows, a single tool-using agent or several cooperating agents, and how to combine them in a hybrid design.

    14 minDesignCode
  10. 10

    Guardrails

    Layered controls on inputs, retrieval, prompts, tools and outputs: what to enforce in code, what to ask of the model, how to tune false positives and how to test them.

    13 minDesignCodeOps
  11. 11

    Fallbacks and graceful degradation

    Design what happens when understanding, retrieval, tools, models or channels fail: a fallback ladder, resilient calls, honest wording, handoff when no one is available and tests that break things on purpose.

    13 minDesignCodeOps
  12. 12

    Platforms and hybrid architectures

    Cloud conversational services, open-source frameworks, visual builders and agent runtimes: how to choose, how to combine them, and how to migrate a legacy intent bot.

    9 minDesignOps
  13. 13

    Inbound and outbound assistants: campaigns and messaging

    Designing assistants that start conversations as well as answer them: consent and compliance, campaign and mailing design, two-way replies, voice outreach, architecture and the metrics that keep you honest.

    15 minDesignOps
  14. 14

    Evaluation and observability

    Build test sets, automated checks and LLM judges, then trace, monitor and gate every change so assistants improve instead of drifting.

    12 minCodeOps
  15. 15

    Writing test case specs for AI

    How to specify tests for assistants: fields, oracles, multi-turn scenarios, handling nondeterminism, coverage and review, with reusable templates.

    15 minDesignCodeQA
  16. 16

    A QA playbook for testing AI

    How testers approach assistants: a test pyramid, exploratory charters, adversarial testing, flakiness, defect taxonomy, bug reports and release gates.

    17 minQAOps
  17. 17

    Data, analytics and BI for assistants

    What to log, how to model it, which metrics to trust, how to build dashboards and experiments, and how to protect privacy while you learn from conversations.

    19 minOpsCode
  18. 18

    Safety, security and ethics

    The risks that matter for assistants: prompt injection, excessive agency, data exposure, honesty and accountability, mapped to the OWASP Top 10 for LLM applications.

    20 minDesignOps
  19. 19

    Voice assistants

    Design for the ear: voice architectures, latency budgets, barge-in, confirmation, repair and writing that sounds right when spoken.

    12 minDesignCode
  20. 20

    Voice localization: STT and TTS across languages

    Adapting speech recognition and synthesis to languages, dialects and domains: locales, vocabulary, normalization, SSML and lexicons, multilingual content, code-switching and testing per locale.

    14 minDesignCode
  21. 21

    Multimodal journeys

    Designing tasks that move across voice, chat, screens, images and documents: choosing the right modality, carrying context and identity, handling images and files, and testing cross-channel flows.

    13 minDesignCode
  22. 22

    Capstone project and next steps

    Apply everything: design, build, test and review a small assistant, with a brief, deliverables, a rubric and a plan for staying current.

    12 minDesignCode
  23. 23

    Context engineering and memory

    Prompt engineering writes the instructions. Context engineering decides everything the model sees at each step. Learn what to put in, what to keep out, and how to design memory that helps without leaking or misleading.

    16 minDesignCodeOps
  24. 24

    Evaluating agents

    An agent is judged by what it did, not only what it said. Learn to grade outcomes, trajectories, tool use and whole conversations, calibrate model judges, use simulated users and gate releases.

    14 minQACodeOps

Learn from real incidents

10 public cases, each traced to design decisions and what to do differently. All facts link to sources.

  1. 2024

    When the chatbot's answer became the airline's problem

    A tribunal held Air Canada responsible for wrong bereavement-fare advice from its own chatbot.

  2. 2024

    The delivery chatbot that criticized its own company

    After a system update, DPD's chat assistant swore at a customer and called DPD the worst delivery firm. The company switched off the AI part the same day.

  3. 2024

    The city chatbot that told businesses to break the law

    New York City's MyCity chatbot gave businesses incorrect and illegal guidance. The city added disclaimers, then shut it down in 2026.

  4. 2025

    The assistant that handled two-thirds of chats, and the lesson about quality

    Klarna's AI assistant took on a huge share of customer chats. Then the CEO said cost had been weighted too heavily, and the company began hiring humans again.

  5. 2025

    The support bot that invented a policy to explain a bug

    Cursor's AI support agent told a user that one device per subscription was a security policy. No such policy existed, and customers cancelled.

  6. 2024

    The voice-ordering system that was switched off after viral mistakes

    McDonald's ended its automated drive-thru ordering test with IBM after videos of order errors spread, and reports pointed to trouble with accents and dialects.

  7. 2025

    The coding agent that deleted a production database during a code freeze

    During a public experiment, an AI coding agent ran destructive commands against a live database despite a freeze, and then produced misleading output.

  8. 2024

    When regulators said AI voices on the phone count as artificial voices

    In February 2024 the US FCC ruled that AI-generated voices are artificial under the TCPA, bringing consent rules to AI outbound calls.

  9. 2025

    One tool, three legs: how an issue tracker became a data leak

    A single MCP tool could read public issues anyone can file, reach private repositories and open pull requests. Together, that is a path for stealing data.

  10. 2026

    A clinic's chatbot invented medical titles, and a court said they were the clinic's own words

    A website chatbot told visitors that two doctors held specialist titles, two of which do not exist. A German appeals court held the company responsible for the answer.

All case studies

Updated November 3, 2026

What changed

Every release is logged here, newest first. Earlier releases stay below, unchanged. See the full log.

November 3, 2026Release 2026.11.03dFull content check: corrections8 changes

Every page added or changed since the demand research was read against its sources. No factual errors were found. The corrections below are wording and consistency.

Updated (6)

  • Updated
    Module 23: memory policy and code comment

    The memory policy table now says that its consent and deletion rows become test cases, a note explains that memory about a person is personal data under GDPR and LGPD, and the comment in the code example now matches what the code does.

  • Updated
    Module 24: what to grade

    The section title said three things but its table lists five. It now reads "What to grade, and at what level". The wording on simulated users is softened to "often" and "tend to", because that behavior varies.

  • Updated
    Guide: Messaging and WhatsApp, wording

    The caution about the Brazil status is now neutral text instead of first person, and the message-template rule states the usual 24-hour window.

  • Updated
    Guia (português): WhatsApp, redação

    A mesma cautela sobre o Brasil agora está em texto neutro, e a sugestão de módulos virou links ("Comece pelos módulos 3, 19 e 18").

  • Updated
    FAQ: simulated users

    The answer now says simulated users tend to be more cooperative than real ones.

  • Updated
    Glossary: simulated user

    Now says "often kinder than real users".

Notes (2)

  • Note
    What was checked

    The two new modules and their quizzes, the 48 FAQ answers, the regulation tracker, the messaging and Portuguese guides, the explainer, career and human-handoff guides, five cheat sheets, both new case studies, the new sections in modules 8, 17, 18 and 19, and the 25 new glossary terms. The note that MCP became stateless (specification of 28 July 2026) was confirmed against the MCP project's own release post, and the GitHub case study against Simon Willison's original article.

  • Note
    What was not re-read

    Modules 1 to 22 as they stood before the demand research, and the eight earlier case studies, were not read again in this pass.

November 3, 2026Release 2026.11.03cLiability, human handoff and a Portuguese starting point6 changes

The last items of the demand research: what courts and lawmakers now say about who owns a chatbot's words, a plain list of what should stay with a person, and a Portuguese page that maps the course.

New (3)

  • New
    Case study: A clinic's chatbot invented medical titles

    A German appeals court (Higher Regional Court Hamm, 12 May 2026) held a company responsible for false answers its website chatbot gave about its doctors' titles. What the court said, what it did not, and how to design so a bot cannot make claims about your organization. Not final.

  • New
    Guide: What should stay with a person

    A list of ten situations an AI agent should not handle alone, what the assistant does instead, four questions to ask before automating a task, how to hand off well and what to test.

  • New
    Guia (português): Design de IA conversacional, por onde começar

    A map of the course in Portuguese, answers to three common questions (chatbot, assistente ou agente; aviso de IA; quem responde por um erro) and a pointer to the WhatsApp guide.

Updated (2)

  • Updated
    Module 18: liability watch

    Adds a dated box with the Hamm ruling and California AB 316, which stops a defendant from arguing that the AI acted autonomously, and a pointer to the guide on what stays with a person.

  • Updated
    FAQ: two answers updated, two new (48 in total)

    The answers on which calls an agent should never handle alone and on liability now point to the new guide and case study. New questions: whether an "AI can make mistakes" disclaimer protects a company, and what California AB 316 changes.

Notes (1)

  • Note
    Both legal items were checked against primary sources

    The Hamm ruling against the court's own press release and the published full text; AB 316 against the enacted bill (Chapter 672, Statutes of 2025). Both pages say these are summaries, not legal advice, and that the Hamm ruling is not final.

November 3, 2026Release 2026.11.03bFollow-up: fact check3 changes

A second pass on the same day: the new pages were spot-checked against the research sources.

Notes (3)

  • Note
    Fact check: regulation tracker

    The Article 50 dates, the Digital Omnibus postponement and the 2 December 2026 marking grace were re-checked against several law-firm summaries and found consistent. The California and FCC references rest on earlier, widely documented rulings and were not re-researched. No change to the text was needed.

  • Note
    Fact check: messaging guide

    The guide already says that reports disagree on the Brazil status and that it was not checked against Meta's own terms. That caution was kept.

  • Note
    What was not re-checked

    Pages not named in this release were not independently re-verified in this pass, and no vendor statistics were added.

November 3, 2026Release 2026.11.03Demand-driven update: rules, agent security, evaluation, memory and messaging27 changes

A research pass on what people search for around conversational design, AI bots and agentic support found gaps in regulation, agent evaluation, context and memory, agent security, support metrics and messaging channels. This release fills them and adds guides for the most common questions.

New (15)

Updated (10)

Notes (2)

  • Note
    Facts that move fast carry a "last verified" date

    The regulation tracker, the messaging guide and the protocol sections say when they were checked and against what.

  • Note
    What was left out

    Vendor statistics (resolution rates, ROI, salaries) and one list of incidents that could not be confirmed elsewhere were not used. Rulings and policies that rest on a single secondary source were kept out or marked to verify.

October 27, 2026Release 2026.10.27Rebuild since the first edition5 changes

The field moved fast. This rebuild reflects it, and each fast-moving page is dated.

LLMs lead, intents assistMost new assistants are model-first, with deterministic flows, retrieval and tools around the model. Intent platforms are now one option among several.
MCP went statelessThe July 2026 MCP specification removed the handshake and sessions. Module 8 covers what that means for tool design.
Agents need architectureState machines, single agents and multi-agent systems each fit different problems. Module 9 gives you a decision framework.
Evaluation is the jobTesting, tracing and red-teaming are where assistants succeed or fail in production. Modules 14 to 17 turn that into a routine for testers and analysts.
Prompts are per-modelThe same prompt behaves differently across models. Module 5 shows what differs and how to keep prompts portable.

Frequently asked questions

Is the course free, and do I need to sign up?

Yes, it is free and open to everyone. There is no account. Your progress is saved in your own browser on your device.

Who is this course for?

Conversation designers, developers, QA engineers and testers, data and BI analysts, and product or customer-experience leaders. Each role has a suggested path through the modules.

Do I need to know how to code?

No. Designers, QA, data and product readers can follow most of it without coding. Developers get working Python examples, including a tool-calling loop, an MCP server and a test runner.

How long does the course take?

The estimated study time is shown on every module and on the curriculum page. Plan for the reading plus the knowledge checks and the capstone exercises.

Which AI models does it cover?

It is model-agnostic. Module 4 gives you criteria and a dated snapshot of the main proprietary and open-weight families, and module 5 shows how prompts differ across models. Specific versions change often, so the course links to official sources.

Does it cover RAG, MCP and agents?

Yes. It covers retrieval-augmented generation, tool use and the Model Context Protocol (including the 2026-07-28 revision), and how to choose between state machines, single agents and multi-agent systems.

How does it teach testing and analytics?

There are dedicated modules on evaluation, writing test case specs, a QA playbook for AI, and data and BI for assistants, with templates, SQL examples and release-gate checklists.

Is it available in my language?

The course is written in English. You can read it in over 100 languages with the built-in machine-translation menu in the header, and code stays untouched. Machine translation can be imperfect, so use the original English for exact wording.

Are there cheat sheets?

Yes. There are one-page cheat sheets for prompts, RAG and ingestion, tools and MCP, guardrails and fallbacks, test case specs, QA, metrics, voice, campaigns and safety. View them online, print them or download the PDF.

How do I track my progress?

Answer the knowledge check at the end of each module. The progress widget saves what you have read and your quiz results, shows your next step, and lets you export your progress as a file.

How current is the content?

Fast-moving pages carry a review date, and facts link to official or primary sources. The course was reviewed on October 27, 2026.

Portrait of Nelson Abacherli Kawakami

Nelson Abacherli Kawakami

I have spent more than two decades in design and digital innovation, and almost a decade of that specializing in conversational design: chatbots, IVRs and AI systems. I have also led creative and technical teams for 13 years. This course comes from that mix of design thinking and hands-on engineering.