🧍Knowing Your Users
Personas, JTBD, segments, and the disciplined practice of staying connected to the people you build for.
Most PM mistakes trace back to building for an imagined user rather than a real one. Disciplined user knowledge — segmentation, personas, JTBD — is the antidote and a competitive advantage.
There's no such thing as 'the user.' There are user segments with different goals, contexts, and constraints. The PM's job is to know the top 2-3 segments deeply, prioritize among them ruthlessly, and update the picture continuously as the customer base evolves.
The three lenses on a user
Segments. Behavioral or attribute-based groups. "Small business owners with 1-5 employees on Shopify" is a segment. "Heavy users of our analytics product" is another. Segments are how you slice the customer base for prioritization.
Personas. Composite representations of a segment. Sara, the SMB owner who runs payroll on Sundays from her phone. Personas are how you keep humans visible during product debates. Personas without segmentation underneath are useless theater.
Jobs to Be Done (JTBD). The functional, emotional, and social outcome a user hires your product to achieve. "When I'm preparing for my Sunday standup, I want to skim my team's week so I can show up sharp on Monday." JTBD is segment-agnostic — multiple personas can share a job.
Why JTBD is more useful than demographics
Demographics tell you who the user is. JTBD tells you why they'd use your product. Two 35-year-old founders in San Francisco might hire completely different products for the "send a quick update to my team" job — Slack, email, Loom, a status doc. The job is the signal; demographics are the noise.
How to actually know your users
- Talk to 5 per week. Forever.
- Sit with sales/support once a quarter. Their patterns are different from yours.
- Watch session replays. 30 min/week. You'll see what you're doing wrong in ways no survey reveals.
- Track segment-level metrics. D7 retention by acquisition channel, conversion by company size, NPS by tier. Aggregate metrics hide everything.
- Write a "user landscape" doc. One page summarizing your segments, their JTBDs, and what each cares about. Update quarterly.
The trap of the loudest user
Three users in a Slack channel screaming for Feature X is not data. It's a sample of one segment, vocal users — likely your power users, who are not your growth bottleneck. The fix: triangulate any vocal-user demand with quantitative data ("how many users in segment Y are hitting this?") before prioritizing it.
The other trap: building for yourself. If you're a PM at Notion and you primarily use Notion for your own work, you're building for one user — you. The job is to build for the millions of users whose context is nothing like yours.
Key frameworks
Users 'hire' products to do jobs. Focus on the job, not the demographics.
Personas without segments underneath are theater. Always pair them.
Map the user's end-to-end experience from awareness to advocacy. Identify the moments of pain and delight.
Real-world examples
Notion's growth team explicitly segments users by 'role' (PM, engineer, founder, student) and tracks adoption metrics per persona. Different onboarding, different template galleries, different upsell triggers per persona. The discipline drove much of their 2021-23 expansion.
Go deeper — recommended reading
Interview questions (1)
Q1How do you decide which user segment to prioritize?strategymid▼
Three filters:
- Size and growth. Which segment represents the largest current revenue, and which is growing fastest? Sometimes those are different — be explicit which one you're optimizing for.
- Strategic fit. Which segment matches where the company is trying to go in 2-3 years? A B2C product company adding enterprise should over-invest in enterprise even if SMB is still the revenue base today.
- Defensibility. Which segment, if you win, creates a moat? Network effects, switching costs, ecosystem lock-in.
The wrong filter: 'which segment is loudest in our Slack community.' That's a vocal-minority bias.
Once chosen, declare it explicitly. "We are building for [segment] for the next 2 quarters; we will deliberately under-invest in [other segments]." Making the trade-off visible prevents drift.