How do you understand that a developer correctly understood the requirements? Were there cases when the developer implemented something that was not needed? At what stage did you notice and what was the reason?

A correct understanding of requirements by the developer can be identified by several signs:

• The developer asks clarifying questions if something is unclear.
• During intermediate demonstrations, the relevant logic and functionality are visible.
• Test scenarios and acceptance criteria match the implemented functionality.

There have been cases where the developer implemented not exactly what was needed. Usually, this was identified during testing or demonstration to the customer. The reason is often insufficiently clearly formulated requirements or lack of feedback at intermediate stages. To avoid such situations, it is important to:

• Agree on requirements with the developer in writing.
• Hold regular meetings and review intermediate results.
• Use prototypes or mock-ups to visualize requirements.