Incrementally route specific capabilities to the new system while the old platform continues serving the rest. Start with read‑only mirrors, then write paths. This limits blast radius, offers measurable wins, and gives time to refine domain boundaries before extracting the next vine.
Choose one region, segment, or product line to trial the custom stack under real demand. Run both systems in parallel, compare outcomes, and maintain rapid rollback. Publishing honest dashboards builds trust while your team hardens performance, observability, and operational muscle memory.
Quantify savings from license reductions, support deflection, and automation, alongside revenue lifts from new capabilities. Don’t forget depreciation and capitalized software rules. Tie milestones to measurable outcomes so the business sees progress monthly, not just at a distant, heroic finish line.
List failure modes, likelihood, impact, and mitigations. Prepare rollback plans that are practiced, not theoretical, with data reconciliation paths and communication trees. When leaders know the escape routes, they greenlight bolder experiments, and teams execute calmly even under bright lights.
Balance product squads with a dedicated migration task force. Clarify ownership of legacy, bridge, and new components. Bring security, finance, and legal into ceremonies early. Momentum improves when every stakeholder sees their role, decisions arrive quickly, and blockers surface before they metastasize.