Square's product development is guided by the principle that "a seller should never outgrow Square." This forces them to build a platform that serves businesses from their first sale at a farmer's market all the way to operating in a large stadium, continuously adding capabilities to manage growing complexity.

To scale, Deliver needed a self-serve system for a high-stakes transaction: taking custody of a merchant's entire inventory. They achieved this by building systems that fostered trust through radical transparency, like photo evidence for discrepancies. This proved self-serve can work for complex, high-trust sales.

Contrary to popular belief, successful entrepreneurs are not reckless risk-takers. They are experts at systematically eliminating risk. They validate demand before building, structure deals to minimize capital outlay (e.g., leasing planes), and enter markets with weak competition. Their goal is to win with the least possible exposure.

Unlike other tech verticals, fintech platforms cannot claim neutrality and abdicate responsibility for risk. Providing robust consumer protections, like the chargeback process for credit cards, is essential for building the user trust required for mass adoption. Without that trust, there is no incentive for consumers to use the product.

Early on, Tock turned down restaurant groups eager to sign up. The founders knew their product lacked features crucial for those clients, and a premature onboarding would lead to failure and churn. By saying "not yet," they protected their reputation and successfully signed those same clients years later.

Building a fully self-serve product doesn't just cater to small customers. Companies like Square and Figma found that large, sophisticated users often prefer to sign up and explore advanced features on their own. This creates a powerful bottom-up adoption wedge inside large organizations, bypassing traditional top-down sales.

To serve its largest customers, Square's open platform is crucial. It allows enterprises to integrate their preferred third-party tools with Square's core services. This flexibility prevents churn by allowing customers to customize their tech stack instead of being locked into a closed ecosystem.

While competitors focus on software, Square believes designing hardware "from the chip up" is a key advantage. This control allows for a superior, integrated experience for both customers and staff at the physical counter, making the technology feel seamless and delightful.

Validate market demand by securing payment from customers before investing significant resources in building anything. This applies to software, hardware, and services, completely eliminating the risk of creating something nobody wants to buy.