James Kennedy welcomes back Eamon O’Sullivan, partner at OSA McQuillan, to unpack how he transformed a traditional, deadline-driven accounting practice into a “service-as-a-subscription” model. Eamon shares the playbook: moving from feast-or-famine annual work to predictable monthly revenue, switching referrals to marketing-led growth, going remote, and the billing tech that makes it hum. If you run a professional services firm (accounting, legal, fractional CFO, consulting), this one’s a blueprint for a calmer business with better margins.