1) Tell the manager that "sold" it to the customers 2) Create a clear list of planned features with him (if you haven't already) 3) Priorize the features. I.e

1) Tell the manager that "sold" it to the customers 2) Create a clear list of planned features with him (if you haven't already) 3) Priorize the features. I.e. find out the ones that where really promised to the customers (the manager knows). Usually it's just 1-2 key features that sell the product. 4) Focus just on those and code properly. Especially if you are doing a rewrite / modernization. What's the point of having a new product, that is hacked spaghetti code from the beginning?