Andrey Bratiashin contributed to the profcomff/rating-api and profcomff/rental-api repositories, focusing on backend feature development and robust API testing. He enhanced the rating-api by adding user_fullname support to the comment system, improving user identification and discussion context, and maintained migration hygiene using Alembic and SQLAlchemy. In the rental-api, Andrey expanded and refactored Item Type API tests, introducing parameterized scenarios and comprehensive error handling to increase test reliability and coverage. Working primarily in Python, he emphasized code clarity, maintainability, and safe schema evolution, demonstrating depth in backend development, database migration, and automated testing practices throughout his contributions.