The best way to do this is through extensive testing and a thorough understanding of the purpose and requirements for the software. Testing can and should range from basic unit testing and integration testing to system-wide testing. These tests will make sure the software is functional, efficient, and meets the requirements. To make sure the software is secure, it is important to perform dependency tests and check for potential breaches like XSS and SQL Injection. The design of the system also plays a role in this. Using the correct architectures can make sure that you are set up to write a good program.
Interpreting user needs starts with an understanding of why they want X feature. For example, let's say a user needs to be able to update certain dates on their calendar app. The user wants to do this because appointments change, and it is something they will be doing often. With this understanding, you can begin to think about what parts of the software will have to change to incorporate this. Not only the date may change but descriptions, titles, and tags. In the backend, there should be an endpoint to update each of these columns in the database. It may be interesting to also add a place in the database to track when an attribute was last edited. All of this is to give the user more adaptability within the software. We do this because while the user needs to update the date in specific, what they really want is more adaptability. This level of understanding user needs is what separates great software from just good software.
Designing software involves understanding user needs, creating a high-level architecture, detailing component designs, implementing code, and testing. This ensures the software is well-designed, meets user needs, and functions as expected. Software design also involves considering scalability, security, and maintainability, ensuring that the software can grow with the user base, protect sensitive data, and be easily updated and improved over time. It's a complex process that requires a combination of technical expertise and an understanding of user behavior and needs.