We modernize a legacy system one slice at a time — each slice proven to match the legacy before it carries live traffic, with the business running the entire way. No big-bang cutover, no frozen roadmap, no "trust us."
Most modernization fails the same way: a multi-year rewrite that tries to replace everything at once, freezes the roadmap, and loses the undocumented rules the old system quietly enforces. We work the other way. AI-accelerated discovery reads the legacy and captures what it actually does as living specs your team owns. Then we modernize one bounded slice at a time onto a modern stack, prove that slice behaves identically to the legacy under real traffic, and only then cut it over. The legacy keeps serving the business the entire time — until, slice by slice, it carries no traffic at all. The four pages below break down exactly how that runs.
Start with the approach for the week-to-week mechanics, or jump to the part you need.
The harder the system is to replace, the more a parity-first, no-big-bang approach is the only one that survives contact with production.