We are seeking a Customer Success Manager (CSM) with proven SDR management or SDR agency experience to join our team. This role is pivotal in driving retention, optimizing campaign performance, and strengthening client relationships across agency portfolios. The ideal candidate thrives in fast-paced environments, balances strategic oversight with hands‑on execution, and brings a strong background in SDR operations. What You'll be Responsible For: Portfolio Management & Strategic Growth Own Campaign Success: Lead and manage end-to-end portfolio campaigns for SSDR Agency and Whistle OS. Drive Retention: Act as the primary relationship manager focused on client retention, ensuring contractual compliance, alignment of scope, and a target of 85% quarterly portfolio MRR retention. Identify Growth Opportunities: Spot upsell and cross‑sell opportunities, manage expansion initiatives, and maintain a clear pipeline with conversion tracking to unlock revenue potential. Client E...