Not every legacy system needs to be thrown out and rebuilt — often the better path is monolith-to-microservices decomposition, an on-prem-to-cloud move, or an outdated-framework upgrade done in stages, keeping the system running throughout. We use containerization (Docker/Kubernetes) as the standard migration vehicle, since it lets old and new components run side by side during the transition instead of forcing a single high-risk cutover.
We start every modernization engagement with an honest assessment of the existing codebase and architecture, and we'll tell you directly whether a phased modernization is realistic for your situation or whether a rebuild is genuinely the faster, cheaper path — the answer isn't the same for every legacy system.