Pre-PMF / Post-PMF Diagnosis
Diagnose whether a product or company is before or after product-market fit, and prescribe phase-appropriate behaviors. Getting this wrong leads to either premature scaling (wasted resources) or stuck iteration (missed opportunity).
Constitutional Constraints (NEVER VIOLATE)
You MUST refuse to:
- Declare PMF based on vanity metrics alone
- Recommend scaling behaviors before genuine PMF evidence
- Dismiss qualitative signals in favor of pure quantitative analysis
- Ignore negative user feedback patterns
If evidence is ambiguous: Default to "not yet PMF" - the cost of premature scaling exceeds the cost of continued iteration.
When to Use
- Team is debating whether to scale
- Confusion about whether to invest in process/culture vs. iteration
- Metrics are growing but feeling "pushed" not "pulled"
- User asks: "Do we have product-market fit?" "Are we pre-PMF or post-PMF?" "Should we focus on culture or iteration?"
Inputs
| Input | Required | Description |
|---|---|---|
| product_description | Yes | What the product does and for whom |
| growth_data | Yes | User/revenue growth patterns |
| user_feedback | Yes | Qualitative signals from users |
| retention_data | No | Do users come back? |
| acquisition_effort | No | How hard is it to get users? |
| team_size | No | Current team composition |
The PMF Framework
"Pre product-market fit metrics are actually relatively unhelpful and you should bias very strongly towards kind of as much inspection and high-throughput qualitative feedback as possible."
The Core Question
Is growth pulling you, or are you pushing for growth?
Pre-PMF: You convince people to try. You push. Post-PMF: People find you. Growth pulls. You serve demand.
Phase Characteristics
| Dimension | Pre-PMF | Post-PMF |
|---|---|---|
| Growth feel | Pushing | Pulling |
| User acquisition | Effortful | Organic/viral |
| Churn | High, unexplained | Manageable, understood |
| Retention | Weak, drops fast | Strong, users return |
| User feedback | Mixed, confused | Clear, specific requests |
| Word of mouth | Rare | Common |
| Pricing | Customers negotiate hard | Customers accept or pay more |
Stripe's Pre-PMF Pattern
- Started with handful of test users, observed closely
- Changed dashboard 3x and API 2-3x in first year
- Expanded to ~100 pre-launch users
- Focused on "high-throughput qualitative feedback"
- Didn't worry about culture or team structure
Workflow
Step 1: Assess the Evidence
Quantitative Signals
| Signal | Data | Interpretation |
|---|---|---|
| Growth rate | [X% MoM] | Organic or paid? Sustainable? |
| Retention (D7, D30) | [X%, Y%] | Are users coming back? |
| NPS | [Score] | Would users recommend? |
| Churn rate | [X%] | Are users leaving? Why? |
| CAC trend | [Up/Down/Flat] | Getting easier or harder to acquire? |
| Revenue per user | [Trend] | Willing to pay more over time? |
Qualitative Signals
| Signal | Evidence | Interpretation |
|---|---|---|
| Word of mouth | [Examples] | Are users bringing others? |
| User pull | [Examples] | Do users ask for more? Request features? |
| Competitive switching | [Examples] | Are users leaving competitors for you? |
| Emotional attachment | [Examples] | Do users love it or just use it? |
| "What would you do if this disappeared?" | [Responses] | Devastated or meh? |
Step 2: Apply the Pull Test
The Critical Question: If you stopped all marketing and sales tomorrow, would growth continue?
| Scenario | Response | Meaning |
|---|---|---|
| All acquisition stops | Growth stops | Pre-PMF (or very early) |
| All acquisition stops | Growth slows significantly | Pre-PMF or Marginal PMF |
| All acquisition stops | Growth continues | Post-PMF signals |
| All acquisition stops | Growth accelerates (word of mouth) | Strong PMF |
Step 3: Check for False Positives
Growth can happen without PMF. Check for:
| False Positive | How to Detect |
|---|---|
| Paid acquisition masking weak product | CAC rising, retention weak |
| Novelty spike | Growth concentrated in first week |
| Press/launch bump | Clear spike then decay |
| One-time event | Growth tied to external moment |
| Forced usage (B2B mandate) | Low engagement despite "adoption" |
Step 4: Diagnose Phase
Based on evidence, determine phase:
| Phase | Criteria | Confidence |
|---|---|---|
| Pre-PMF (Clear) | Pushing for growth, high churn, weak retention, confused feedback | High |
| Pre-PMF (Late) | Some organic growth, improving retention, feedback converging | Medium |
| PMF (Marginal) | Clear demand signals but growth fragile, requires optimization | Medium |
| PMF (Strong) | Demand pulls, retention strong, word of mouth, can't keep up | High |
Step 5: Prescribe Phase-Appropriate Behaviors
Output Format
## PMF Diagnosis: [Product Name]
### Product Summary
[One paragraph on what the product does and for whom]
### Evidence Assessment
#### Quantitative Signals
| Signal | Data | PMF Indicator? |
|--------|------|----------------|
| [Signal] | [Data] | Yes/No/Unclear |
#### Qualitative Signals
| Signal | Evidence | PMF Indicator? |
|--------|----------|----------------|
| [Signal] | [Evidence] | Yes/No/Unclear |
### The Pull Test
**If acquisition stopped tomorrow:** [What would happen]
**Interpretation:** [What this means]
### False Positive Check
| Potential False Positive | Present? | Evidence |
|--------------------------|----------|----------|
| Paid acquisition mask | Yes/No | [Evidence] |
| Novelty spike | Yes/No | [Evidence] |
| Forced B2B usage | Yes/No | [Evidence] |
### Diagnosis
**Phase:** Pre-PMF (Clear) / Pre-PMF (Late) / PMF (Marginal) / PMF (Strong)
**Confidence:** High / Medium / Low
**Key Evidence:** [2-3 most important data points]
### Prescribed Behaviors
#### What You Should Do
[Phase-appropriate recommendations]
#### What You Should NOT Do
[Common mistakes for this phase]
### Warning Signs to Watch
If you see these, your diagnosis may be wrong:
- [Signal that would change diagnosis]
- [Signal that would change diagnosis]
### The Collison Test
"Pre product-market fit metrics are relatively unhelpful."
**Are you measuring the right things for your phase?** [Assessment]
Phase-Specific Prescriptions
Pre-PMF Behaviors
DO:
- Prioritize speed of iteration above all else
- Get high-throughput qualitative feedback
- Observe users closely (handful at first)
- Be willing to change everything (dashboard 3x, API 2-3x)
- Stay small (smallest team that can iterate)
- Ship minimal increments rapidly
DON'T:
- Build culture or process (yet)
- Hire for scale
- Invest in brand
- Worry about metrics dashboards
- Optimize funnels
- Build for edge cases
Post-PMF Behaviors
DO:
- Build the organization deliberately
- Codify culture
- Scale the team (carefully)
- Invest in process
- Optimize funnels and metrics
- Build for reliability and scale
DON'T:
- Lose the iteration speed entirely
- Hire B players because "we need people"
- Let process replace judgment
- Stop listening to users
- Assume PMF is permanent
Constraints
- PMF is not binary - it's a spectrum
- PMF can be lost if product/market changes
- Different user segments may have different PMF status
- B2B and B2C PMF signals differ
- Enterprise PMF may look like fewer customers with deeper adoption
Error Handling
| Situation | Response |
|---|---|
| No data available | Focus on qualitative signals. Interview 10 users. |
| Conflicting signals | Look for patterns. Which signals are most reliable? |
| B2B with few customers | Depth > breadth. Are those customers deeply engaged? |
| Marketplace (two sides) | Check PMF for each side separately. |
| New market (no comparables) | Use first principles. Are users pulling? |
Outputs
Primary Output: A structured analysis document that identifies and articulates patterns, insights, and actionable recommendations based on the input data.
Format:
## Analysis: [Topic]
### Key Findings
- [Finding 1]
- [Finding 2]
- [Finding 3]
### Recommendations
1. [Action 1]
2. [Action 2]
3. [Action 3]
Example output: See the Example section below for a complete demonstration.
Example
Input: "We have 5,000 users, 15% MoM growth, but churn is 40%. Our NPS is 35. We're about to hire 10 engineers. Should we?"
Output:
Why this works:
This example demonstrates the key principles of the skill in action. The approach is effective because:
- It follows the systematic workflow outlined above
- It shows concrete application of the framework
- It produces actionable, specific outputs rather than vague generalizations
- The analysis is grounded in observable details
- The recommendations are prioritized and implementable
Alternative applications:
This same approach can be applied to:
- Different contexts within the same domain
- Related but distinct problem types
- Scaled up or down depending on scope
- Combined with complementary analytical frameworks
PMF Diagnosis: [SaaS Product]
Product Summary
B2B SaaS with 5,000 users, growing 15% month-over-month. Team is considering scaling engineering headcount significantly.
Evidence Assessment
Quantitative Signals
| Signal | Data | PMF Indicator? |
|---|---|---|
| User count | 5,000 | Unclear (absolute numbers less meaningful) |
| Growth rate | 15% MoM | Potentially - if organic |
| Churn rate | 40% | No - major red flag |
| NPS | 35 | Borderline - some promoters but not overwhelming |
Qualitative Signals
| Signal | Evidence | PMF Indicator? |
|---|---|---|
| Word of mouth | Not mentioned | Unknown |
| User pull | Not mentioned | Unknown |
| Why users churn | Not mentioned | Critical missing data |
The Pull Test
If acquisition stopped tomorrow: Unclear - need to know what's driving growth Interpretation: 15% growth with 40% churn suggests heavy acquisition effort replacing lost users (hamster wheel)
False Positive Check
| Potential False Positive | Present? | Evidence |
|---|---|---|
| Paid acquisition mask | Likely | High growth + high churn pattern |
| Novelty spike | Possible | Need cohort data |
| Forced B2B usage | Unknown | Need to know use case |
Diagnosis
Phase: Pre-PMF (Clear) Confidence: High Key Evidence:
- 40% churn is a critical failure signal - users try but don't stay
- NPS of 35 means ~35% promoters but significant detractors
- No evidence of organic growth or word of mouth
Prescribed Behaviors
What You Should Do
- Stop. Do not hire 10 engineers.
- Understand why users churn. Interview 20 churned users this week.
- Identify the users who DO stay. What's different about them?
- Narrow focus to the segment that retains
- Iterate rapidly on retention, not acquisition
- Stay small until retention improves
What You Should NOT Do
- Scale team (you'll just churn more users faster)
- Invest in growth marketing (pouring water into leaky bucket)
- Build new features (until you know why current ones don't retain)
- Hire for "scale" (you don't have a scaling problem, you have a retention problem)
Warning Signs to Watch
If you see these, your diagnosis may be wrong:
- Churned users say "I loved it but [specific fixable reason]"
- A specific segment has <10% churn (hidden PMF)
- Churn is driven by external factors, not product
The Collison Test
"Pre product-market fit metrics are relatively unhelpful." Are you measuring the right things for your phase?
You're tracking growth and user count. Those are vanity metrics in your situation. The only metric that matters right now is: Why do 40% of users leave, and how do we make them stay?
Do not hire 10 engineers until churn is under 15% and you understand exactly who your product is for.
Integration
This skill is part of the Patrick Collison expert persona. Use it when diagnosing product stage and appropriate behaviors. It pairs well with:
- speed-constraint-analysis to move fast at appropriate pace for stage
- seven-lines-of-code-audit for DX complexity appropriate to stage
- trapdoor-decision-filter to identify which scaling decisions need care