Tentative dateSaturday, September 19, 2026

Build software you can trust with AI agents

AI can write code faster than you can review it. Learn to build test suites, evaluations, and CI guardrails that let you merge agent-written changes with confidence, with Eric Elliott and Jan Hesters.

Sign up for the workshopExplore the workshop
Eric Elliott holding a camera
Eric Elliott

Foundations

Testing

Jan Hesters working on a laptop
Jan Hesters

Tools covered in the workshop

Vitest
Jest
Testing Library
Cypress
React
GitHub Actions
Claude
Cursor
Codex

Turn AI speed into software you can trust in production

Learn how to change code without fear

Choose the right test boundary, avoid false confidence from coverage numbers, and write failures that explain exactly what broke.

Teach your agents to work test-first

Separate test-writer, implementer, and orchestrator roles so an agent never writes code and grades its own work.

Put guardrails around AI velocity

Use prompt evaluations, protected guard suites, smoke tests, and rollbacks to catch mistakes before they reach users.

Built for different starting points

Who is the workshop for?

From junior engineers to senior staff, engineering leaders, and vibe coders, every experience level can learn something. Start with shared foundations, then move into bleeding-edge AI evaluations, multi-agent TDD, and CI guardrails that many teams have not used before.

Refine your craft

Engineers

Whether you are a junior engineer or senior staff, learn to design tests that catch regressions and give coding agents precise feedback. Bring the same standards into reviews, refactors, and your team's daily work.

Ship human and AI-written code with confidence.

Lead with clear standards

Engineering leaders

Learn how to steer quality without micromanaging implementation. Give your team shared standards for coverage, TDD, agent permissions, CI guardrails, and safe AI-assisted delivery.
Ask us about dedicated training for your team.
Unstick AI-built projects

Vibe coders

For when AI fixes one bug and creates two more. Use executable requirements, evaluations, and separate agent roles to stop endless prompting and move your project forward again.

Turn agent output into verified software.

18 modules from first principles to agent pipelines

Learn the system behind trustworthy AI-written software

First, learn how to design tests you can trust. Then teach those standards to your agents and build guardrails that let them move fast without silently breaking production.

01

Foundations

What is a Test?

Learn what automated tests prove, what they cannot prove, and how to read pass and fail states correctly.

  • True and false positives
  • True and false negatives
02

Foundations

Why Test?

Replace repeated manual checks with fast feedback you can run after every human or agent-written change.

  • Automated verification
  • Faster feedback
03

Foundations

What is Test Coverage?

Separate code coverage from case coverage, then use both without confusing a high percentage for confidence.

  • Line, branch, and function coverage
  • User requirements
04

Foundations

What is a Testing Framework?

Understand what test runners and assertion libraries do, and how the major JavaScript tools fit together.

  • Vitest, RITEway, and Jest
  • Playwright and Cypress
05

Test design

Kinds of Tests

Choose the right boundary for each risk instead of forcing every behavior into the same kind of test.

  • Unit, integration, and functional
  • E2E, snapshots, mocks, and spies
06

TDD

What is TDD?

Use red, green, refactor as a tight feedback loop that turns a requirement into verified behavior.

  • Red, green, refactor
  • The scientific method

Your instructors

Who we are

Two perspectives on software design, testing, technical leadership, and building with AI.

Eric Elliott holding a camera

Author, educator, and software engineering expert

Eric Elliott

Eric is the author of Programming JavaScript Applications and Composing Software. He teaches JavaScript, software design, test-driven development, and AI-driven development. His product work includes Adobe, The Wall Street Journal, ESPN, and the BBC.
  • TDD
  • Software design
  • AI-driven development
Read Eric's work
Jan Hesters working on a laptop

CTO, engineering leader, and React educator

Jan Hesters

Jan joined Hopin as its seventh employee and helped grow the company to more than 1,000 employees and a valuation above $7 billion, serving as an engineering manager. He later founded ReactSquad, which embeds engineers with well-known B2B SaaS and ecommerce companies, supports startups, and helps vibe coders turn AI-built products into software they can ship.
  • React
  • Engineering leadership
  • Testing
Learn more about Jan

One price per attendee

One ticket. The complete workshop.

Learn the testing system that turns fast agent output into changes you can verify, review, and merge with confidence, with Eric Elliott and Jan Hesters.

Testing Masterclass ticket

Build the skills first. Then encode them into tests, evaluations, agent roles, and CI guardrails that protect every change.

What's included

  • Workshop attendance
  • Live instruction across all 18 modules
  • Hands-on tests, TDD, and AI evaluation exercises
  • Q&A with Eric Elliott and Jan Hesters
Price per attendee
$45USD
Reserve your seat

Tentatively scheduled for Saturday, September 19, 2026. The time will be confirmed before booking.

What developers say about Eric and Jan

Feedback on Eric's teaching and writing, and on Jan's mentorship and engineering leadership. Workshop attendee reviews will follow after the first session.

“This book is rather fantastic.”

BN
Ben NadelProgramming JavaScript Applications review · Eric Elliott

“An excellent and timely example of how to do it the right way.”

R
RobProgramming JavaScript Applications review · Eric Elliott

“Easy and interesting reading. There are new ideas in it.”

OD
Olexander DanchukProgramming JavaScript Applications review · Eric Elliott

“A great book that doesn't just teach you Functional Programming in JavaScript, but rather teaches you Software Composition using FP.”

SR
Seale RapolaiComposing Software review · Eric Elliott

“A great introduction into functional programming concepts.”

EB
Erin BurtonComposing Software review · Eric Elliott

“Sticking close to him is almost a guarantee for success.”

SS
Sayan SivaneswaranLinkedIn recommendation · Jan Hesters

“He knew how to delegate and let our team work autonomously whilst always being available.”

RF
Ross F.LinkedIn recommendation · Jan Hesters

Before you reserve

Frequently asked questions

The practical details about the curriculum, ticket, and tentative schedule.

Can't find what you're looking for? Email jan@reactsquad.io.