Business Sense for Engineers: The Missing Half of Product Sense
Authors: Sidwyn Koh and Hannah Stulberg | Published: 2026-04-25
Product sense tells you what to build. Business sense tells you why it matters. You need both.
Why This Matters
- Engineer-to-PM ratios are rising at companies like Anthropic, Cursor, OpenAI
- Decisions that used to sit with PMs now need to be made within engineering
- Product sense’s fifth component (strategic thinking) requires deep business sense to function
The Four Components of Business Sense
1. How a Company Makes Money (P&L and Unit Economics)
Key metrics:
| Metric | What it measures |
|---|---|
| CLV (Customer Lifetime Value) | Total profit a customer generates over full relationship |
| CAC (Customer Acquisition Cost) | Cost to acquire one new customer |
| Payback period | Time to earn back CAC |
| ARPU (Average Revenue Per User) | Revenue per active user in a period |
| Churn rate | Percentage of customers who leave. Often the single biggest input into CLV |
2. Business Model Fluency
Five common tech business models: subscription, marketplace, SaaS, advertising, transaction-based.
Pricing model != business model:
- Business model: “How does the company fundamentally make money?”
- Pricing model: “How do we charge for it?”
- Example: Spotify = subscription business with freemium pricing. Slack = SaaS with usage-based seat overages
The business model determines how to measure feature success. A recommendation engine optimizes for different outcomes depending on the model (stickiness in SaaS, time on site in advertising, transaction volume in marketplace).
3. Market Sizing
- Core question: how many customers could we sell to, and how much would they pay?
- Applies at all levels: entire markets, features on a roadmap, technical investments
- Famous example: Uber’s seed pitch estimated $4B TAM. Bill Gurley argued $300B+ because materially improving an offering expands the market
- In practice, engineers size features more than markets. Sequence matters: business priorities set which problems need investment; sizing tells you which solutions are the best bets
4. Competitive Landscape and Right to Win
Six questions:
- Who are the real competitors (direct, indirect, non-consumption)?
- What are they good at?
- What’s the deciding factor when customers choose?
- Where are you winning/losing?
- What’s your moat?
- Where is the market heading?
Five common moats: network effects, switching costs, economies of scale, brand, distribution
Examples:
- Stripe (switching costs): Clean APIs and fast integration. Once teams shipped on Stripe, rewriting for a legacy processor was unthinkable
- Microsoft Teams (distribution): Bundled free with Microsoft 365 across 345M existing seats. By 2020: Teams 320M DAUs vs Slack 42M. The moat shaped the product strategy, and the product strategy won
How to Build Business Sense
- Trace your team’s metrics to the P&L. Follow OKRs to a business outcome (revenue, retention, cost reduction)
- Attend one business review. Just listen. Write down unfamiliar terms and look them up
- Read the financials. Public: read your 10-K. Private: ask finance for a 30-minute P&L walkthrough. Tip: drop a 10-K into NotebookLM for a podcast
Key Takeaway
There are always more good product ideas than any team can build. Business sense is the skill of picking the one that will actually move the business.