Technical Debt becomes really toxic when mission critical customer facing functionality is based on it. Just this morning we received a ticket where cleaning up technical debt caused a major issue for the customer, when we looked even further we realized that this customer relied heavily on the state brought on by technical debt and that resolving this issue will require an even more careful refactoring to ensure that the debt is cleared but the overall functionality is unchanged.

As a workaround for the time sensitive issue we literally copied the old code and overloaded our class so that the customer runs the old code while we develop a robust fix.