Explore the challenges of maintaining code that unexpectedly becomes production-critical in this 30-minute conference talk from EuroPython 2024. Dive into the world of Hypothesis, a Python library for generating diverse test inputs, and learn how it can help ensure the reliability of evolving data analysis code. Discover the benefits of Hypothesis's Ghostwriting feature, which leverages type hints to automatically generate tests, saving time and validating code structure. Gain insights into the process of enhancing ghostwritten tests to thoroughly examine both inputs and outputs, ultimately improving the robustness of your analytical code that may transition from one-off scripts to mission-critical applications.