When selecting a backend framework, scalability is the factor I prioritize most. From experience, scalability isn't just a "nice to have"-it's essential for any project with growth potential. As a product's user base and data requirements expand, the backend needs to handle this increased load without compromising performance or stability. A scalable framework allows us to add features, handle more requests, and grow the infrastructure seamlessly, reducing the risk of costly re-architecture down the line. A framework built with scalability in mind often includes support for horizontal scaling, efficient database integrations, asynchronous processing, and robust resource management. This choice makes a huge difference in how well the backend can adapt to evolving needs, ensuring we're prepared for high traffic and complex operations. By selecting a framework that facilitates this from the start, we're investing in the long-term health of the product and the experience we deliver to users.