Katarina, co-founder of Diva and software engineer, discusses technical debt in software development - when it's beneficial, how to manage it, and strategies for dealing with it. She explains that while technical debt often has negative connotations, planned technical debt can actually help teams deliver value faster in certain situations like MVPs and rapid prototyping. The talk covers approaches for managing different sizes of technical debt and presents data showing that organizations who actively manage technical debt ship features 50% faster.

The speaker discusses strategies for modernizing and refactoring legacy PHP applications. He covers the challenges of dealing with old, poorly structured codebases and presents a methodical approach to upgrading them using the 'strangler fig' pattern. The talk emphasizes the importance of securing buy-in, implementing code standards gradually, and carefully migrating functionality to new systems while maintaining business operations.