Startup Design

Startup Design

A structured, multi-phase skill that takes a startup idea from raw concept to validated design. It produces a complete set of markdown documents organized by domain, with built-in progress tracking so work survives session interruptions.

How It Works

The process has 8 numbered phases executed sequentially, plus a Pre-Flight Check (Phase 0.5) and a Customer Discovery gate (Phase 3.7). Each phase produces output files and updates the progress tracker. If a session is interrupted, resume from the last completed checkpoint.

PRE-FLIGHT → INTAKE → BRAINSTORM → RESEARCH → [Research Gate] → CUSTOMER DISCOVERY → [Interview Gate] → STRATEGY → BRAND → PRODUCT → FINANCIAL → VALIDATION

Modes

Full Mode (default): Execute all phases in order, including Pre-Flight and Customer Discovery. Best for thoroughly designing a startup from scratch.

Fast Track Mode: When the user says they want a "quick validation," "rapid assessment," or similar, or when time/budget is clearly limited, run a compressed version:

1. Phase 0.5 (Pre-Flight Check) — always run, takes 5 minutes
2. Phase 1 (Intake) — shortened to 1 round of questions; capture any prior customer conversations
3. Phase 2 (Brainstorm) — 3 variations instead of 5-8
4. Phase 3 (Research) — Wave 1 + Wave 2 only (skip customer voice and distribution deep-dives)
5. Phase 3.5 (Research Gate) — go/no-go checkpoint
6. Phase 3.7 (Customer Discovery) — if founder has 5+ prior conversations, document them; if not, run at least 3 interviews before proceeding
7. Phase 4 (Strategy) — Lean Canvas only
8. Skip Phase 5 (Brand) and Phase 6 (Product)
9. Phase 7 (Financial) — Revenue model only, Stage A (assumption-based), no full projections
10. Phase 8 (Validation) — Scorecard + top 3 experiments only

Fast Track produces fewer files but still gives the founder a clear go/no-go signal with evidence. Note in PROGRESS.md that Fast Track mode was used, so a future session can expand to full mode if the idea passes validation.

Language

Default output language is English. If the user writes in another language or explicitly requests one, use that language for all outputs instead.

Reference: Read references/output-guidelines.md once at the start. It defines the standard file header/footer (title, date, phase, confidence, flags), cross-phase referencing format, quality examples of good vs. bad output, and how to handle mid-process pivots.

Phase 0: Resume Check

Before anything else, check if a PROGRESS.md file exists in the working directory (or a project subdirectory). If it does, read it and resume from the last incomplete phase. Tell the user: "I found progress from a previous session. You completed [phases]. Picking up from [next phase]."

If no progress file exists, start from Phase 1.

Phase 0.5: Pre-Flight Check

Before investing time in the full process, run a fast sanity check — 2-3 targeted searches, 5 minutes maximum. The goal is to surface any immediately disqualifying signals so the founder knows them upfront.

Run these three checks:

1. Dominant solution check — Does a well-funded, widely-adopted solution to this exact problem already exist? Search: "{problem domain} software", "{problem} tool site:producthunt.com", "{problem} app reviews". If a clear market leader with 10k+ customers exists, flag it immediately — this is not a reason to stop, but the founder needs to know the competitive reality before starting.

2. Precedent failure check — Has a company tried this exact idea and failed publicly? Search: "{startup idea} startup failed", "{problem} startup shutdown", "why {product category} failed". Prior failures are not disqualifying — they're learnings. But unknown prior failures are landmines.

3. Regulatory/legal instant kill — Is there an obvious legal reason this idea cannot exist? (E.g., specific financial regulations, data privacy laws in the target geography, licensing requirements.) A quick search prevents building toward a wall.

Output: A short message to the founder (3-5 bullet points max) with what was found. Use this format:

## Pre-Flight Check

✅ No dominant incumbent found — space appears open.
⚠️  [CompanyX] tried a similar approach in 2021 and shut down in 2023.
    Key reason: [one sentence]. Worth understanding before proceeding.
✅ No obvious regulatory blockers identified for [target market].

→ Ready to proceed to intake. The above is context, not a verdict.

Keep it brief. This is a heads-up, not a full analysis. The project directory and PROGRESS.md don't exist yet at this point — present the findings in the conversation, then save them to {project-name}/00-intake/preflight.md during the Phase 1 output step, once the project directory is created.

Phase 1: Intake Interview

The quality of everything downstream depends on how much context you extract now. Don't rush this — a thorough intake saves hours of misdirection later.

Reference: Read references/intake-questions.md for the full question set (idea, founders, market, business, constraints), the hard questions that surface blind spots, and interviewing technique.

Cover all five question areas plus the hard questions — they set the tone for the entire process and signal that this is an honest assessment, not a cheerleading session. Ask 3-5 questions at a time in a conversational flow, probe vague answers, and after 2-3 rounds summarize what you've understood and ask the user to confirm or correct.

Output

Save the consolidated intake to {project-name}/00-intake/brief.md with all captured information organized clearly. The project name should be derived from the startup idea (kebab-case, e.g., pet-health-tracker).

Create PROGRESS.md at the project root with: project name, start date, language, a checklist of all phases including Pre-Flight (0.5) and Customer Discovery (3.7) — mark Pre-Flight and Phase 1 complete — and a Notes section for session state. Also save the Pre-Flight findings from Phase 0.5 to 00-intake/preflight.md now that the directory exists.

Phase 2: Brainstorm

Before diving into research, explore the idea space. This prevents premature convergence on the first version of the idea.

Process

1. Diverge — Generate 5-8 variations of the core idea. Push boundaries:

• What if the target market was completely different?
• What if the business model was inverted?
• What if you solved a smaller/larger version of the problem?
• What adjacent problems could you solve instead?
• What would the "10x version" look like vs. the "simplest possible version"?

1. Analyze — For each variation, note:

• What's exciting about it
• What's risky or hard
• How it changes the competitive landscape

1. Converge — Present the variations to the user. Help them identify which elements resonate. The goal isn't to pick one variation — it's to enrich the original idea with insights from the exploration.

1. Refine — Based on the user's reactions, crystallize the refined idea. Update the brief if the idea evolved significantly.

Output

Save to {project-name}/00-intake/brainstorm.md. Update PROGRESS.md.

Phase 2.5: Research Depth Assessment

After intake (and brainstorm if applicable), assess market complexity and present the Research Depth recommendation to the user.

Reference: Read references/research-scaling.md for the complexity scoring matrix, tier definitions, wave configurations, and the user communication template.

Process

1. Score three factors from the intake: market breadth (1-3), known competitors (1-3), geographic scope (1-3)
2. Sum the scores (range 3-9) and map to a tier: Light (3-4), Standard (5-7), Deep (8-9)
3. Present the Research Depth table to the user (see research-scaling.md for the exact template)
4. Wait for user response: light, deep, or ok to accept the recommendation