I start with questions like - - What are the engineering and business benefits of refactoring the current code base? - What is the cost of not refactoring code base? Does it affect user experience, performance of the app? - Does it significantly improves onboarding time for new engineers? - Does it enable the team to incorporate future updates or feature development? etc. Any engineering tech-debt has to be justified with outcomes, and needs to be weighed against current priorities. Else it will be a waste of critical resource.