I’m going through the same thing at the moment. I’ve come in two years after the project was started, where the key strategy was to replace a in-house developed

I’m going through the same thing at the moment. I’ve come in two years after the project was started, where the key strategy was to replace a in-house developed maze of spaghetti that had become unmaintainable, with a collection of SaaS based services interconnected with a bunch of synchronization queues and services moving data around. The initial plan as I arrived was to write V2 in its entirety, migrate the data from V1 as one bug bang rewrite and job done. I realized immediately that the risk there was far too dangerous and the goals unrealistic, so I’m pushing for the strangler pattern and the business is pushing back. However I’m finally getting people in the business to understand the new plan I’ve put together and they are seeing opportunities. Still, almost all the old developers have left and the existing system is running on duct tape. There are no tests. The old system is a fat client with a bunch of half finished messaging services as the improvement project for the original system was cancelled with lots of workarounds going direct into a central database and most of the business logic is buried in the UI. Even understanding how it all fits together is impossible, so the only way forward is to go back to basics and work with the business departments to design and document the process they REALLY need and iteratively build it. You’ll never really feature match and business departments develop workaround processes over time that become the norm, to the point that they become inefficient by historical lack of design. Going back to basics in terms of process design is something I highly recommend. Your biggest challenge is that the business will be pushing engineering to deliver and they will continuously try to push deadlines on the engineering department that you won’t be able to realistically deliver. All you can do is keep pushing back, keep on trucking and try not to let it get to you and your engineering teams. Remember to take a deep breath once in a while. Let the waves crash over you and try not to take it all personally.