In my previous role as a Software Engineer, I was developing a new API endpoint for a critical feature that allowed users to update their profile information. The project had a tight deadline, and I was under pressure to deliver quickly. During the development, I introduced a bug where a specific field's validation (email format) was bypassed if the user updated other profile details simultaneously. I mistakenly believed the front-end validation was sufficient for all scenarios. The mistake became apparent when a user reported being unable to log in after updating their profile with an invalid email, and logs showed the invalid email had been persisted. Upon discovering this, I immediately pushed a hotfix that added server-side validation for all critical fields, regardless of the update path. To prevent future issues, I implemented an automated regression test specifically for data validation across all API endpoints. Furthermore, I initiated a team discussion to standardize our validation practices, emphasizing server-side validation as the primary defense, and introduced a mandatory peer code review checklist that included a specific point for comprehensive data validation. This not only fixed the immediate bug but significantly strengthened our API's data integrity and our team's development process.

The STAR method is a structured approach to answering behavioral interview questions. It stands for:

• Situation: Set the scene and provide necessary details about the context.
• Task: Describe your responsibility or role in that situation.
• Action: Explain what you did to address the situation or complete the task.
• Result: Share the outcomes of your actions, including what you learned.