Build the Right Thing

Product engineering for software developers

AI Engineer World's Fair 2026

Thesis

When AI agents level the implementation playing field,

the differentiator becomes building the right thing.

Let's wake up

Your brain needs this đź§ 

Slido

Help choose the example app

Slido QR code

kcd.im/aie-2026-qa

Submit ideas for the example app

We’ll use this for Q&A too. Add questions or upvote them as we go.

Presenter controls

Set the live example

Updates the URL query param and all visible app placeholders without reloading.

AI changes the scarce resource

Less scarce

Implementation gets cheaper, faster, and more widely available.

More valuable

Deciding whether the work is worth building in the first place.

“Can we build it?”

“Is it worth building?”

Product engineers understand which targets are worth hitting

Human arrows Agent arrows A small target range Many possible targets

AI agents make more targets reachable.

Product engineers decide which ones deserve the effort.

When building gets cheap, ideas matter more

Upcoming Ben Ilegbodu

Become an Epic Product Engineer

“It’s once development becomes cheap and easy and enables anybody to be able to do it, especially non-technical people, then it’s really about the ideas that you have.”

Ben Ilegbodu

Worth having is the hard question

Julius Marminge

Become an Epic Product Engineer · Episode 08

“deciding whether a feature is worth having or what the long-term consequences are.”

Julius Marminge

The danger is confidently building the wrong thing

Looks done

The code is clean. The tests pass. The ticket is closed.

Still failed

Finished implementation can still produce no customer value.

Shipping the wrong thing faster is still the wrong thing.

The right thing comes before the thing right

Wayne Allan episode artwork

Become an Epic Product Engineer · Episode 02

“The product concern is building the right thing and the engineering concern seems to be building the thing right... building the thing right is downstream of building the right thing.”

Wayne Allan

Agents make the wrong work faster too

Dax Raad

Become an Epic Product Engineer · Episode 01

“The default place for our new coding agent abilities to go to is to work on the wrong things. Products going from good to bad faster than ever.”

Dax Raad

Bad practices move faster now

Upcoming Shaundai Person

Become an Epic Product Engineer

“It’s accelerated everything, all of the bad practices. And it’s given us the tools that we need to move bad faster.”

Shaundai Person

Real-looking prototypes can lie

Upcoming Rita Kozlov

Become an Epic Product Engineer

“it’s very easy for it to look and feel real very quickly... Why can’t I just ship this, right?”

Rita Kozlov

Surface-level function is not enough

Upcoming Rita Kozlov

Become an Epic Product Engineer

“you can build something that you know at the surface level seems functional. But is not actually scalable or doesn’t address any of the edge cases that a user is going to encounter.”

Rita Kozlov

False progress feels productive

Aaron D. Francis

Become an Epic Product Engineer · Episode 04

“You can do the wrong thing incredibly fast and feel like you’re making a ton of progress... how do I do the right thing incredibly fast or at least directionally correct rather than do 10,000 lines of code a day on the wrong freaking thing.”

Aaron D. Francis

Product engineering is not engineers becoming PMs

Engineers need enough product judgment to shape technical investment toward real customer progress.

Product engineers connect customer understanding to technical choices

The technical choices matter:

Data model
Workflow shape
Observability
Constraints
Failure modes
Smallest useful slice

Get in the truck

Robert C. Martin

Story · Become an Epic Product Engineer · Episode 19

Customer context changes the software

Phone repair truck. Customer context changes the software.

Robert C. Martin

Half technology, half customer

Robert C. Martin

Become an Epic Product Engineer · Episode 19

“A product engineer lives half in the technology and half in the customer’s house... There’s this deeply human side to product engineering.”

Robert C. Martin

Engineering judgment comes from technical experience

Grady Booch

Become an Epic Product Engineer · Episode 13

“What’s different for me about a software engineer is that we have judgment... knowledge of computer science. ... knowledge of algorithms and architecture and the human issues.”

Grady Booch

The goal is not the API

Upcoming Ronan Berder

Become an Epic Product Engineer

“The end goal is not I built an API that just... did what we agreed on doing. The goal is to go and launch a product that is successful, secure, scale well, and performs well in the end for the end user.”

Ronan Berder

The engineering shape is part of the product decision

The same product request can imply very different technical commitments.

Architecture is where change gets expensive

Grady Booch

Become an Epic Product Engineer · Episode 13

“All architecture is design, but not all design is architecture. Architecture represents the set of significant design decisions... where significant is measured by cost of change.”

Grady Booch

Find the right primitives

Rhys Sullivan

Become an Epic Product Engineer · Episode 10

“If you don’t have the right primitives, it becomes so much harder to build your products... Find the right primitives and build a great product out of that.”

Rhys Sullivan

Distribution is a product decision

Upcoming Michael Grinich

Story · Become an Epic Product Engineer

WorkOS cloud API

Fast fixes and security updates changed the right distribution model.

Michael Grinich

Coding agents need a safe playground

Agents are only as useful as the environment, constraints, and feedback loops we give them.

LLMs need a prepared environment

Ruben Casas episode artwork

Become an Epic Product Engineer · Episode 15

“Someone behind the scenes needs to create the right environment for LLMs to be productive and to be safe... boundary, good products and platform architecture and taste and safeguards and testing.”

Ruben Casas

Agents need to see the product

Upcoming Ben Ilegbodu

Story · Become an Epic Product Engineer

TV UI

No browser loop. Build agent visibility into the product environment.

Ben Ilegbodu

Twelve agents can create twelve patterns

Upcoming Shaundai Person

Story · Become an Epic Product Engineer

Architecture drifts

Twelve agents. Different patterns. Architecture drifts.

Shaundai Person

Systems engineering is still human

Robert C. Martin

Become an Epic Product Engineer · Episode 19

“You can’t tell the agent to make you a massive airport control system... You would have to tie them all together. So the systems engineering is still completely human.”

Robert C. Martin

Without product insights

What goes wrong when engineers only receive solution-shaped tickets?

You overbuild or underbuild in the wrong places

Aaron D. Francis

Become an Epic Product Engineer · Episode 04

“We can’t blame the user for having a bad solution. They know nothing about the architecture underneath, but if we can find out what they’re trying to do, we might find a nice neat home in the existing architecture...”

Aaron D. Francis

You lose stakeholders

Upcoming Erin Fox

Story · Become an Epic Product Engineer

Technical work still needs a product story

Migration framed as tech work. Stakeholders drift.

Erin Fox

Who is this disagreement in service of?

Alex Hillman

Become an Epic Product Engineer · Episode 09

“who is this disagreement in service of?”

Alex Hillman

You lose users because of unintentional feature bloat

Upcoming Ben Ilegbodu

Become an Epic Product Engineer

“If we’re able to deliver three times better, do our users actually want three times more features?”

Ben Ilegbodu

You design the wrong thing but blame the user

Don Norman

Story · Become an Epic Product Engineer · Episode 06

Three Mile Island was a design failure

Smart operators. Bad system design. Don’t blame users.

Don Norman

Workshop outline

You are going to leave with frameworks for making engineering decisions for your own product.

Early idea validation

The Mom Test

Framing user requests

Jobs Theory

Prioritizing software changes

Kano Model

So, what’s the idea we’re going with?

Questions

Slido QR code

kcd.im/aie-2026-qa

Before we get into it, let’s look at your questions

Early idea validation

We’ve got an app idea: [example app].

How do we validate it?

Activity: audience brainstorm

Give me some questions you’d ask people to validate [example app].

Framework 1

The Mom Test

The Mom Test book cover Rob Fitzpatrick

Rob Fitzpatrick

Don’t ask users to evaluate your idea or diagnose the problem for you.

Weak

“Would you use this?”

“Is this a problem?”

“What is the problem?”

Better

“Tell me about the last time this happened.”

“What did you do instead?”

“What did it cost?”

Symptoms are not the problem

Don Norman

Become an Epic Product Engineer · Episode 06

“Don’t ask somebody what’s the problem, because they’ll tell you the symptoms.”

Don Norman

Ask about specific past behavior

  • Tell me about the last time this happened.
  • What happened?
  • Who was involved?
  • What made it annoying enough to remember?

Ask what they do today instead

Look for:

Workarounds
Cost
Frequency
Existing effort

Ask what they already tried or paid for

Stronger evidence

Existing effort is stronger evidence than stated interest.

Weak pain

If they have never tried to solve it, the pain may not be strong enough yet.

Talk, ask, listen

Wayne Allan episode artwork

Become an Epic Product Engineer · Episode 02

“Talk to people, ask good questions, and listen.”

Wayne Allan

Find the cost of inaction

Upcoming Michael Grinich

Become an Epic Product Engineer

“what were you losing out by not having it? Like what was the cost by not doing this?”

Michael Grinich

Output: interview evidence, not validation theater

A good interview should change the shape of the idea.

An idea that skipped validation

Wayne Allan episode artwork

Story · Become an Epic Product Engineer · Episode 02

Built for all of Australia

Nobody came.

Wayne Allan

Test the market before the full build

Wayne Allan episode artwork

Become an Epic Product Engineer · Episode 02

“We probably could have launched something in two weeks and done the integration manually... We could have tested the market and learnt a lot of things very, very quickly and not invested a whole team.”

Wayne Allan

Show it to people

Upcoming Michael Grinich

Become an Epic Product Engineer

“It’s very easy to convince yourself that something is a good idea, just sitting in your room by yourself hacking on it for weeks and weeks and weeks... So you need to show it to people.”

Michael Grinich

Close the loop with users

Ruben Casas episode artwork

Become an Epic Product Engineer · Episode 15

“The user feedback is what closes the loop... the quicker you get it to your users, the quicker they know, yes, this solves my problem, or this is not worth pursuing.”

Ruben Casas

Why product engineers need The Mom Test

Translation

PMs may own discovery, but engineers own translation into system shape.

Appropriate architecture

Past behavior tells engineers which architecture is appropriate.

Without that context, engineers may faithfully build the wrong abstraction.

Framing user requests

Now we’ve got [example app] implemented and we’re rapidly adding features based on user requests.

Request comes in: [example request].

Or use a request in your own product.

Presenter controls

Set the live request

Updates the URL query param and all visible request placeholders without reloading.

Keep asking why

Jack Ryan

Become an Epic Product Engineer · Episode 11

“The number one thing is to figure out why... You need to understand what they want [the button] to do... and then they need to tell you why they want it to do that... until three or four layers deep...”

Jack Ryan

Framework 2

Jobs to Be Done

Competing Against Luck book cover Clayton Christensen

Clayton Christensen et al.

People “hire” products to help them make progress in a specific situation.

Jobs Theory source: Competing Against Luck for the hire/progress framing.

The request is not the job

Original request: [example request].

Upcoming Rita Kozlov

Become an Epic Product Engineer

“People will say, you guys should build this feature. And then you ask them... what are you trying to solve? ... if you do say yes to every one of these features, you do end up with a level of complexity...”

Rita Kozlov

Don’t nail requests onto the product

Jack Ryan

Become an Epic Product Engineer · Episode 11

“We don’t just take feature requests and nail them onto the thing that we’ve already got. It won’t be a good product. There’s loads of judgment that takes place there.”

Jack Ryan

Situation creates the job

Not

users want X

But

When I’m in situation Y, help me make progress Z without W.

Write the job statement

When [situation], help me [make progress], so I can [desired outcome].

Activity: write one job statement for [example request] (or the request on your own product).

Break the job into three dimensions

Functional

What progress are they trying to make?

Social

How does this affect how they are seen by others?

Emotional

How do they need to feel?

How to make your thing win like React won thumbnail

Upcoming BWK episode: How to make your thing win like React won

Let customer signal wash over you

Jack Ryan

Become an Epic Product Engineer · Episode 11

“We have Slack channels which just feed in feedback from sales calls... all of that is really useful context that you can kind of let it wash over you.”

Jack Ryan

Situate the product in a life

Upcoming Michael Grinich

Become an Epic Product Engineer

“There’s something very important in thinking about the storytelling of the thing you’re building, how it situates in someone’s life.”

Michael Grinich

Translate the job into system shape

Functional

State, workflow, integration, success signal

Social

Visibility, permission, ownership, approval, history

Emotional

Preview, undo, confirmation, explanation, recovery

Production means accountability

Upcoming Rita Kozlov

Become an Epic Product Engineer

“if you’re gonna be committing code to production, you’re then accountable for that code and... need to really own it and fully understand... the end to end architecture...”

Rita Kozlov

Define success by repeated progress

Forces you to answer:

  • How do we measure progress?
  • Do they do this more than once?
  • What should we build, change, instrument, defer, or not build?
  • What does [example request] become after we understand the job?

Why product engineers need Jobs Theory

  • The job gives engineers language for system-shape questions.
  • Functional, social, and emotional progress point to different product and architecture needs.
  • Without the job, we can build the requested feature while missing the system users actually need.

Prioritizing software changes

Our product is now safely across the chasm in the hands of the majority.

We’re getting lots of requests.

What are some good requests?

Not all features create value the same way

Wayne Allan episode artwork

Become an Epic Product Engineer · Episode 02

“[Bun] had all these other ideas, which were really exciting, but they kind of missed some foundational ideas. And so there’s actually a mental model for this. It’s called the Kano model.”

Wayne Allan

Framework 3

Kano model

Attractive Quality and Must-Be Quality framework reference Noriaki Kano

Noriaki Kano

Not all features create value the same way.

Original source: the 1984 paper Attractive Quality and Must-Be Quality.

How to Prioritize Software Tasks thumbnail

Published BWK episode: How to Prioritize Software Tasks

Basics do not delight when present, but they punish you when missing

Wayne Allan episode artwork

Become an Epic Product Engineer · Episode 02

“If there’s no toilet paper at my hotel, that’s a bad experience. But if I have 100 rolls of toilet paper, it doesn’t increase my good experience of a hotel.”

Wayne Allan

Fix foundations before chasing delighters

Dillon Mulroy

Become an Epic Product Engineer · Episode 03

“You can’t waste your time on doing delightful stuff before getting the foundations right... Focus on foundations and primitives. Make sure you have good feedback systems...”

Dillon Mulroy

Why product engineers need the Kano Model

PMs and product partners help identify value. Engineers decide the reliability, reversibility, permanence, and technical commitment that value deserves.

Basics

Reliability, completeness, durable ownership

Performance

Measurable quality gradients

Delighters

Reversibility and low architectural commitment

Indifferent

Do not make permanent product surface area

Reverse

Avoid turning user harm into architecture

Recommendation frame

  • The target worth hitting is ___ because ___.
  • The smallest technical shape is ___.
  • Before building, we should validate ___ by ___.
  • The smallest useful version is ___.
  • We will know it worked if ___.

Conclusion

Early Idea Validation

The Mom Test

Framing User Requests

Jobs Theory

Prioritizing Software Changes

Kano Model

Remember

When AI agents level the implementation playing field,

the differentiator becomes building the right thing.

Thank you

EpicProduct.engineer

EpicProduct.engineer
Q&A QR code

kcd.im/aie-2026-qa