How to choose a .NET partner for a SaaS rewrite

Rewriting a SaaS product is one of the highest-stakes decisions a product owner can make. The wrong partner can burn a year and leave you worse off than you started. The right one buys you a foundation that compounds for the next five years.

1. Look for an opinion, not a menu

The strongest signal that a partner takes the work seriously is that they have opinions. Opinions about architecture, about test strategy, about how to phase a migration. Generic "we can do anything you need" is a red flag — it usually means they'll do whatever you say, even when you're wrong.

2. Ask how they'd phase the rewrite

A serious partner will refuse to commit to a big-bang rewrite. They'll talk about strangler-fig patterns, vertical slices, and how to keep the old system safe while the new one is built around it. If the proposal is "we'll rewrite everything in 12 months and switch over", run.

3. Ask to see code, not just decks

Any partner can produce a deck. Far fewer can show you a representative production codebase and explain the decisions inside it. Ask. Read it. If it looks like clever sketches and not maintainable software, that's the work you'll be inheriting.

4. Look for predictable delivery, not heroics

Heroic delivery sounds good in a sales conversation. It usually means an unstable team and burnt-out engineers. Predictable delivery — two-week cycles, real demos, honest "we're slipping a week" updates — is the boring superpower you actually want.

5. Check the maintenance plan

What happens after launch? A partner that disappears once the contract ends is a partner that doesn't believe in their own work. Ask for the maintenance model, the SLA, and what an "ongoing improvement backlog" looks like in their other engagements.

None of this is exotic. It's just specific. Specificity is what separates engineering partners from sales organizations with engineers attached.