[lazerscience]

Working incrementally definitely makes sense. Also if you don't see a chance to do it in an incremental way you should probably take a step back and ask yourself if the old application is maybe too huge and monolithic and check if there's a possibility to make it more modular. So you could split one huge application in smaller parts/services which can easier evolve seperately from the rest.

[troels]

Very much agree. Slicing the existing application up in smaller parts and migrating those piecemeal is another form of incremental rewriting, as opposed to working through one layer at a time.