Most work fits one of three shapes. Which one you need usually depends on how well-defined the problem already is.
3–6 weeks
A short, fixed-scope assessment of where you are against where you want to be. Ends in a ranked list of constraints and a sequenced roadmap — not a proposal. You can take it to another firm and we would consider that a fair outcome.
3–12 months
A team that works inside your process, on your board, against your definition of done. We staff for transfer from day one: your people pair with ours, and documentation is part of the increment rather than a phase at the end.
Ongoing
We run the thing we built, or the thing you already had, against agreed service levels. Includes the unglamorous parts — on-call, patching, capacity, cost review — and a quarterly conversation about what should be automated away next.
Describe the problem in a paragraph and we'll tell you which of the three we'd propose — or that none of them apply.