Own the complete post-sale customer lifecycle for B2B SaaS accounts, including onboarding, rollout coordination, issue resolution, account health, renewals, retention, and expansion. Lead cross-functional customer calls, uncover friction and upsell opportunities, document feedback, escalate operational issues, maintain accurate account records, and develop standardized customer success playbooks. The role requires high autonomy, urgency, strong communication, and technical comfort with CRM and workflow tools.