Describe a bug you missed in production and what you changed in the process to avoid repeating it.

One of the bugs I missed in production was related to incorrect handling of boundary values in the input form. As a result, when entering certain data, the system did not show an error but simply ignored the input, leading to data inconsistency.

After the incident, I changed the testing process as follows:

• Introduced boundary and negative scenario checks into test plans.
• Added automated tests covering these cases.
• Implemented peer-review of test cases with colleagues to identify gaps.
• Used checklists for regression testing to avoid missing important scenarios.

This helped significantly reduce the likelihood of missing such bugs in the future.