All of this seems to focus on the code, after glossing over the career management implications in the first paragraph.
I've done this sort of work quite a number of times and I've made mistakes and learned what works there.
It's actually the most difficult part to navigate successfully. If you already have management's trust (i.e., you have the political power in your organization to push a deadline or halt work), you're golden and all of the things mentioned in the OP are achievable. If not, you're going to have to make huge compromises. Front-load high-visibility deliverables and make sure they get done. Prove that it's possible.
Scenario 1) I came in as a sub-contractor to help spread the workload (from 2 to 3) building out a very early-stage application for dealing with medical records. I came in and saw the codebase was an absolute wretched mess. DB schema full of junk, wide tables, broken and leaking API routes. I spent the first two weeks just bulletproofing the whole application backend and whipping it into shape before adding new features for a little while and being fired shortly afterwards.
Lesson: Someone else was paying the bills and there wasn't enough visibility/show-off factor for the work I was doing so they couldn't justify continuing to pay me. It doesn't really matter that they couldn't add new features until I fixed things. It only matters that the client couldn't visibly see the work I did.
Scenario 2) I was hired on as a web developer to a company and it immediately came to my attention that a huge, business-critical ETL project was very behind schedule. The development component had a due date three weeks preceding my start date and they didn't have anyone working on it. I asked to take that on, worked like a dog on it and knocked it out of the park. The first three months of my work there immediately saved the company about a half-million dollars. Overall we launched on time and I became point person in the organization for anything related to its data.
Lesson: Come in and kick ass right away and you'll earn a ton of trust in your organization to do the right things the right way.
I've done this sort of work quite a number of times and I've made mistakes and learned what works there.
It's actually the most difficult part to navigate successfully. If you already have management's trust (i.e., you have the political power in your organization to push a deadline or halt work), you're golden and all of the things mentioned in the OP are achievable. If not, you're going to have to make huge compromises. Front-load high-visibility deliverables and make sure they get done. Prove that it's possible.
Scenario 1) I came in as a sub-contractor to help spread the workload (from 2 to 3) building out a very early-stage application for dealing with medical records. I came in and saw the codebase was an absolute wretched mess. DB schema full of junk, wide tables, broken and leaking API routes. I spent the first two weeks just bulletproofing the whole application backend and whipping it into shape before adding new features for a little while and being fired shortly afterwards.
Lesson: Someone else was paying the bills and there wasn't enough visibility/show-off factor for the work I was doing so they couldn't justify continuing to pay me. It doesn't really matter that they couldn't add new features until I fixed things. It only matters that the client couldn't visibly see the work I did.
Scenario 2) I was hired on as a web developer to a company and it immediately came to my attention that a huge, business-critical ETL project was very behind schedule. The development component had a due date three weeks preceding my start date and they didn't have anyone working on it. I asked to take that on, worked like a dog on it and knocked it out of the park. The first three months of my work there immediately saved the company about a half-million dollars. Overall we launched on time and I became point person in the organization for anything related to its data.
Lesson: Come in and kick ass right away and you'll earn a ton of trust in your organization to do the right things the right way.