Sven Johann talks with Dave Thomas about innovating legacy systems. Dave clarifies first why legacy systems are both valuable and problematic. Next, they discuss bad systemic and good incremental approaches for innovation of legacy systems; why you shouldn't rewrite an old system but rather focus on tactical changes to reduce cost or increase productivity within one quarter; examples of how to measure success of the innovation; how to get full support from management to use any technology you want; when cleaning up the codebase makes sense and when not; good ideas to innovate the codebase; approaches to introduce tests; and how to deal with data