Explore a conference talk from PHP UK 2020 that delves into the challenges of handling messy data while maintaining clean code. Learn how a major Swiss retailer's API consumes and transforms data not originally designed for the digital age. Discover the journey of dealing with various data sources and formats, and how a robust architecture was built to seamlessly process and output information. Gain insights into maintaining and upgrading an API over a five-year period, including the transition to Symfony 4. Understand the implementation of import commands, third-party data providers, mapper dependencies with compiler passes, and strategies for ensuring quality through testing, logging, and monitoring. Examine the importance of acceptance tests for critical data and the techniques used for serializing, versioning, and grouping data in this informative 45-minute presentation.