It depends on the codebase – but in most cases, a full rewrite is slower, riskier, and more expensive than incremental modernization. A rewrite requires freezing feature development, running two systems in parallel, and betting months of engineering time on a cutover that may not go cleanly. Incremental modernization with feature flags keeps production running throughout and spreads the risk across manageable sprints. The Readiness Scan gives you a concrete recommendation for your specific situation.

This is one of the most common challenges we encounter. As part of the migration process, AI agents generate documentation for every module touched – including components that have never been documented. The codebase you end up with is documented as a byproduct of the migration itself.

With the feature flag migration approach, no. The system migrates incrementally while production keeps running. Your team can continue shipping features in parallel. The Legacy Sprint model (4-week repeatable sprints) is specifically designed to run alongside ongoing product work rather than replacing it.

AI handles the work that makes migration slow and expensive: dependency analysis, code transformation, documentation generation, and test coverage. Your team reviews and approves at every checkpoint. Nothing moves to the next phase without human sign-off. AI accelerates the process – it doesn't replace the judgment calls.

It depends on the size and complexity of the codebase. The Readiness Scan produces time estimates specific to your system before any implementation begins. As a reference point: a well-structured Symfony migration with reasonable test coverage can take half a day with AI tooling. Larger, less structured codebases take longer – and the Readiness Scan will tell you exactly how much longer before you commit.

No. Each phase is a standalone engagement. Some clients come in only for a Readiness Scan to get a migration map they can use internally. Others already have a clear picture of the problem and come directly to BUILD. SCALE is an ongoing retainer for teams that want continuous debt reduction after the initial migration – it's an option, not a requirement.

The Readiness Scan is designed to surface this before implementation starts. If the complexity changes the scope or the timeline, you'll know before any code moves. We give you a go/no-go recommendation with concrete estimates – so there are no surprises mid-migration.