Most teams approach legacy migrations as a single, high-stakes cutover: pick a weekend, flip the switch, and hope nothing breaks. We've found a phased approach is almost always safer and faster in practice.
Start by building the new system behind a routing layer that can direct traffic to either the old or new path per-user or per-feature. This lets you migrate the lowest-risk cohort first, validate it in production under real load, and only then move the next cohort.
The key discipline is treating the legacy system as a fallback, not a relic — keep it operational and in sync until the new system has proven itself with real traffic over real time, not just in staging.
Tell us what you’re building and we’ll reply within one business day with next steps, no sales deck required.