AI · STRATEGIC DESIGN · 0→1 · PROMPT ENGINEERING

STRATEGIC DESIGN · 0→1 · PROMPT ENGINEERING

Rehearsl: AI-assisted tool that role-plays stakeholder personas and scores your pitch into structured feedback

Rehearsl: AI-assisted tool that role-plays stakeholder personas and scores your pitch into structured feedback

Rehearsl simulates the stakeholders you're about to present to, asks what they would ask, and scores how you answer.

Rehearsl simulates the stakeholders you're about to present to, asks what they would ask, and scores how you answer.

ROLE

Product Designer: Strategy, Prompt Engineer, Build

MY CONTRIBUTIONS

Problem Framing, AI Workflow Design, Prompt Engineering, Build, Live Testing, Strategic Analysis

TIMELINE · STATUS

5 Days · Functional Prototype Shipped, Hi-Fi In-progress

01 — SITUATION

The Problem

The Problem

Designers can defend their work on paper and lose it in the room. According to research, alignment with stakeholders is their number-one problem. There is no structured way to practice it to improve designer communication skills.

Why it matters?

Why it matters?

In 2026, NN/g asked 150 designers their number-one problem. Half named the same thing. Not design quality, not research methods, but alignment.

In 2026, NN/g asked 150 designers their number-one problem. Half named the same thing. Not design quality, not research methods, but alignment.

Nielsen Norman Group: What Designers Actually Struggle With on Product Teams

The solution

The solution

Upload your design context, name who you're presenting to, and confirm the AI's summary before it starts. Then it plays each stakeholder, asks what that role would ask, and scores your answers on five dimensions, with fixes tied to what you said.

02 — THE RESULTS

Working Prototype in Five Days

Working Prototype in Five Days

  1. Setup: upload context and define stakeholders

  1. Simulation: one stakeholder at a time, no qustions preview

  1. Feedback: tips anchored to the rehearsal

The most important question in building an AI tool isn’t what the AI does. It’s what the human never gives up.

The most important question in building an AI tool isn’t what the AI does. It’s what the human never gives up.

03— RESEARCH

Have you ever had a great design idea but struggled to explain it to someone who isn’t a designer?

Have you ever had a great design idea but struggled to explain it to someone who isn’t a designer?

Have you ever had a great design idea but struggled to explain it to someone who isn’t a designer?

You know the work is right. Then a CEO or a CTO asks you to justify it on the spot and the words don't come out. I've been there. I'd spend hours writing notes, then answer like a designer: context first, methodology heavy. What the room needed was a business answer in 30 seconds.

Tom Greever names the tension in Articulating Design Decisions: "The most articulate person often wins." You can have the best solution in the room and still lose the meeting. NN/g's State of UX 2026 now lists stakeholder management as a core competency alongside research and design craft. The field has named the gap. It hasn't built a way to practice closing it.

TARGET USER

A product designer who has already done the work and has a meeting with stakeholders who don't think like designers.

Every existing tool solves an adjacent problem. Speech coaches grade how you talk. Deck builders make the slides. None start from your design context, and none simulate the specific people in your specific room.

TOOL

WHAT IT DOES

WHAT IT MISSES

Yoodli · Orai · Speeko

AI speech coaches: pacing, filler words, delivery

Delivery only. They grade how you speak, not what you’re saying about your actual decisions

VirtualSpeech

VR practice environments for public speaking

Immersive but generic. No domain knowledge, no stakeholder specificity

Beautiful.ai · Gamma · Pitch

AI slide generation and deck building

Build the presentation, not the live conversation after you stop presenting

Toastmasters · LinkedIn Learning

General communication skills and courses

Async and generic. No simulation rooted in your work and your stakeholders

Asking a colleague

One honest opinion from someone who knows you

One guess, 10 minutes and they may not know what your CTO actually cares about

THE GAP

None tie feedback to what you said about your own decisions. Rehearsl trains you for this meeting, with these stakeholders, about this design.

04 — FRAMEWORK

Two frameworks became the architecture

Two frameworks became the architecture

Two frameworks became the architecture

FRAMEWORK 1

Who owns each task

For AI to do a task well, it needs something concrete to work with and a way to check the result. Analyzing a context document fits: the input is the file, the output is a summary, and I can tell whether it understood. Knowing what I left out of that document, or the history between me and my CTO, doesn't fit. So AI owns analysis, synthesis, and simulation. I own the context, the judgment, and the approval before coaching starts. That was decided before anything was built, because those tasks are structurally unfit for AI.

TASK

HOW IT HAPPENS TODAY

WHO OWNS IT

Upload the context

.md / .docx / .pptx; 1 minute

Human

Write design context

Designers write it; hours to days

Human

Analyze the context

Memory or intuition; 5 minutes

AI

Deliver the analysis

No structured output exists today

AI delivers. Human reviews & approves

Simulate stakeholders

Not a standard preparation step

AI simulates by role. Human picks the room

Run the simulation

Practice alone, or not at all

AI plays the stakeholder. Human answers

Score & suggest fixes

Doesn’t happen; 5-10 min when it does

AI scores & explains. Human decides what to act on

FRAMEWORK 2

What does good actually look like?

Before designing the workflow, I wrote out what a good version of this tool does and what a bad version does, in specifics. A good version asks probing questions rooted in this designer's project. A bad version cycles through stock prompts like "Tell me about your process." That spec became the master instructions that govern the AI in every session. The "what to avoid" list became hard stops. The "what AI needs to know" list became the pre-session checklist.

05 — DESIGN DECISIONS

Every decision names what it costs. A tool that only lists its strengths is hiding something

Every decision names what it costs. A tool that only lists its strengths is hiding something

Every decision names what it costs. A tool that only lists its strengths is hiding something

01

A human authorization gate before every session

Why

Before coaching starts, the AI writes a five-part summary of what it read and stops until the designer confirms it's accurate.

Tradeoff

Friction at the start of every session. A designer eager to jump in has to slow down. I kept it because it protects everything after.

Tension

It only works if the designer reads the summary. A rushed confirmation defeats it. The tool can prompt you to check; it can't force attention.

A human authorization gate before every session

02

Data-only stakeholder simulation

Why

Trusted sources only: industry research, annual reports, reputable publications. A CTO briefed on your company's priorities asks sharper questions than "What's your timeline?"

Tradeoff

Slower setup. The AI has to research the company and the roles before it can simulate anything useful. Guessing would be faster and also wrong.

Tension

It can simulate a CTO in general. It can't simulate your CTO, their history with you, the unspoken concerns. That gap goes back to the designer.

Data-only stakeholder simulation

03

Limitation transparency at the start of every session

Why

It works well enough to pass for a prediction. Each session opens with what it doesn't know: your stakeholders, the politics, the room's mood.

Tradeoff

The disclaimer gets tedious after enough use. I kept it anyway.

Tension

After enough sessions the disclaimer becomes wallpaper. The tool can repeat the warning. It can’t make you keep taking it seriously.

Limitation transparency at the start of every session

04

Questions appear without preview

Why

If you know the questions in advance you're memorizing answers instead of practicing the skill.

Tradeoff

Harder and less comfortable, especially early. An anxious designer gets no safety net.

Tension

There's no difficulty setting. If it feels overwhelming early, there's no way to ease in. You push through or stop.

05

Scoring tied to what the designer actually said

Why

When you said X, you did Y well, but Z needs work." Every note anchors to a moment and grades how the stakeholder would react.

Tradeoff

The AI has to track every sentence the designer says. When it misses nuance or scores wrong, the format makes the error visible.

Tension

You judge whether the AI is right. Trust it and flawed feedback shapes your practice. It assumes you can already tell when it's wrong.

Scoring tied to what the designer actually said

06

Two-skill architecture with explicit dependencies

Why

A check-context-validation skill runs the check before coaching; a design-stakeholder-coach skill runs the simulation and can't start until that check completes. That dependency is written into the file.

Tradeoff

Two files mean more to maintain and more places for inconsistency. An index file exists to manage that, a catalog of what exists and where.

Tension

The check is enforced in system-prompt.md, design-stakeholder-coach.md, and check-context-validation.md. Skipping it means overriding all three; the AI can't. A designer who rushes the confirmation can.

Two-skill architecture with explicit dependencies

06 — THE PRE-BUILD CRITIQUE

Knowing how to review a skill file mattered more than knowing how to write one

Knowing how to review a skill file mattered more than knowing how to write one

Knowing how to review a skill file mattered more than knowing how to write one

The Self-Imposed Critique That Caught Three Failures

  1. The memory promise. The skill claimed to "maintain continuous memory" across sessions. Each session starts fresh. The critic was right about the problem and misread my intent. The designer should never have to say "refer to last time." The tool should learn from past sessions on its own: how the designer communicates, recurring patterns, areas of difficulty. How that history is stored is still open.

  1. Inferring unwritten dynamics. AI can't infer unwritten rules from a brief description. I moved that responsibility to the designer: the prompt asks what each stakeholder cares about and why, so the designer surfaces the dynamics instead of the AI guessing. The AI coaches within the context provided; the designer owns the political context.

  1. Undefined scoring rubric. Without defined criteria, numerical scores would be arbitrary: two designers could get different scores for similar answers. I replaced the scale with three outcome-based levels tied to likely stakeholder reactions:

Strong: convinced or engaged

Adequate: understands but may still have doubts

Weak: confused or unconvinced

This makes the feedback easier to interpret and more consistent across rehearsals.

07 — THE BUILD

Designed AI behavior through writing, not code

Designed AI behavior through writing, not code

Designed AI behavior through writing, not code

system-prompt.md

The full behavior spec, pasted directly into the Claude Project prompt field.

master-instructions.md

The governing rules: tone, data rules, what the human controls, hard stops.

design-stakeholder-coach.md

The coaching simulation skill, its sequence, and what it must never do.

check-context-validation.md

The verification check: five-part summary, the hard stop, the limitation reminder.

output-first-prompt-sheet.md

The artifact spec that preceded the build: what good looks like, what to avoid.

SKILLS_INDEX.md

A reference catalog of every skill and where to find it.

08 — THE TESTING

I set up a Claude Project with the system prompt and ran a full session with a CEO, CTO, and PM as the room

I set up a Claude Project with the system prompt and ran a full session with a CEO, CTO, and PM as the room

I set up a Claude Project with the system prompt and ran a full session with a CEO, CTO, and PM as the room

What worked well

  1. The AI limitation statement came first

Before the coaching begins, the tool said what it can and cannot know about the real stakeholders.

...I don't know your actual stakeholders as individuals. I don't know the history between you and your CTO, the politics in the room, or how someone's mood that day might shift the conversation. What happens in the real meeting will be different. This is rehearsal, not a prediction.
  1. Rehearsl researched the company

It looked up the company's public mission, strategy, and values before building the stakeholder profiles.

  1. The check before coaching held

The tool gave its five-part summary. For each stakeholder it separated what it had found in public sources from what I had told it, and pointed out that all I had given it was three job titles. It noticed my project and my audience didn't line up, and asked instead of guessing:

"Was this a portfolio review, or a pitch for a product the company would build? The answer changes what every stakeholder would ask."

"Was this a portfolio review, or a pitch for a product the company would build? The answer changes what every stakeholder would ask."

The Context Check, Before a Single Coaching Question

  1. It recovered from a mishearing

When voice input turned my words into "a halt tool," the CEO asked what I meant instead of guessing.

  1. The scorecard caught where I was vague

My answers started broad and only sharpened under follow-up, and the scores say so, tied to what I said:

Clarity: Adequate. I got to a coherent vision, but the CEO had to pull it out of me exchange by exchange.

Handling objections: Adequate. I pivoted when pushed, but didn't push back or show conviction.

Evidence: Weak. Solid research, but I never anchored the pitch to it — never showed why the board-game format specifically solves the barrier the research found.

Evidence: Weak. Solid research, but I never anchored the pitch to it or showed why the format I chose solves the barrier the research found.

Stakeholder alignment: Adequate. Connecting to the company's mission was smart, but I never addressed why it should own a standalone product versus partnering.

Handling objections: Adequate. I pivoted when pushed, but didn't push back or show conviction.

Persuasiveness: Weak. The CEO would understand the idea. They wouldn't be convinced it's a product the company should build yet.

It gave me three fixes: lead with the research insight; connect the product's mechanics to the barrier the research identified; get specific on measurement before the CEO asks. Then it offered three options. I chose to pause and reflect, and got a reflection task.

What Needs improvement

  1. It gave an opinion before coaching started

While it was still confirming its summary with me, it said the companion app "is likely where the product case gets made." That step is meant to check understanding, not to advise. I was not pitching the app.

  1. Voice input misheard me

"Health tool" came through as "a halt tool." The accent fix in What Changed hasn't been tested yet.

  1. Voice output degraded

Voice was the intended delivery mode because it makes the simulation feel like a real meeting. It held for a few minutes, then turned static and robotic, like a walkie-talkie losing signal. The simulation kept working; the voice couldn't sustain it. The limit is the platform's. The concept holds.

What Changed

  1. No more question preview

In an earlier session the tool listed questions for each stakeholder before the simulation and said "Review these so you know what's coming." That removed the on-the-spot pressure the tool exists to create. I added a rule to the system prompt: ask the first question without warning, never preview or list questions. In testing, the CEO asked cold.

  1. Accent handling

Claude's voice feature kept mishearing my accent, so the fix had to come from outside it. I added code that records my voice and sends it to a separate speech-to-text service, with a list of design terms to expect so they come through correctly. Not tested yet.

09 — NEXT STEPS

Where it goes from here

Where it goes from here

Where it goes from here

Hi-fi screens. Full interaction states: loading while the AI reads context, the confirmation screen, the simulation in its active state.

More rounds with different designers. The second round is underway: a different case study, a designer who wasn't involved in building it. The goal is to find where the check fails for someone who doesn't already know how to write a good context document.

Deeper personalization over time. Each session building on the last on its own, and testing whether that changes how designers perform.

Voice, revisited. Once the core is stable, voice on a platform that can sustain it is the next upgrade.

Hi-fi screens. Full interaction states and loads while the AI reads context, the confirmation screen, the simulation in active state.

More rounds with different designers. The second round is underway: a different case study, a designer who wasn't involved in building it. The goal: find where the validation check fails for someone who doesn't already know how to write a good context document.

Deeper personalization over time. Each session building on the last automatically and testing whether that actually changes how designers perform.

Voice, revisited. The concept is right; the technical execution isn't. Once the core is stable, voice on a platform that can sustain it is the next meaningful upgrade.

10 — STRATEGIC REFLECTION

Five places where the tool works and creates a new risk at the same time

Five places where the tool works and creates a new risk at the same time

Five places where the tool works and creates a new risk at the same time

01

Knowledge Extraction

Critical

The tool only works if you share everything: full rationale, stakeholder context, company information. For sensitive or competitive projects, that openness has a cost worth weighing.

Tension

Each session invites you to share more, and trust grows with use. I haven't settled where "enough context to be useful" ends and "more than I should disclose" begins.

02

Workflow Adaptation

Critical

It only works if you've done the work first. Thin context, vague stakeholders, skipped phases, and the simulation is thin. The tool doesn't reduce the prep.

Tension

Am I getting better at communicating decisions, or better at passing a simulation? The real test is whether the clarity holds in a meeting with people who don't follow the script.

03

Compliance and Safety

Critical

A disclaimer only works if you take it in. After enough good sessions confidence feels like certainty, and you walk in believing the simulation was more accurate than it was.

Tension

The tool is honest about what it can't do. Confidence built through repetition can override that honesty in the moment it matters most.

04

Model Operations

Critical

The system prompt is the only thing controlling behavior, and I’m the only one watching it. If the AI shifts after a model update, there’s no alert, no review, no team to catch it. Fine for one person; not fine for a team.

Tension

What made it easy to build, one person and one file with no process, is what makes it fragile for a team.

05

Functional Replacement

Critical

Something less visible than a role is replaced. Asking a colleague "what will my CTO ask?" prepared you and built a relationship. The simulation keeps the first and drops the second.

Tension

The tool is better at being available; a colleague is better at knowing you. If every designer practices alone with AI, the informal coaching between colleagues fades.