Manual modernization typically takes months per application because of handoffs between application, data, and infrastructure teams. Agentic approaches compress this by running those workstreams as coordinated, agent-executed pipelines: Visma cut human effort 40% on a 3-million-line application, and NTT DATA cut time-to-market for data solutions by 50%. Exact timelines depend on estate size, dependency complexity, and governance requirements – which an assessment maps first.