Design and implement end-to-end customer journeys and campaigns in Customer.io across email, SMS, and push notifications. Write clear, compelling, and on-brand copy for all lifecycle marketing communications. Strategically segment user base for personalized messages. Execute A/B tests on subject lines, creative, and timing to improve performance. Analyze campaign results and key metrics for optimization. Collaborate with product and data teams to define customer events and triggers for automation. Maintain organized library of templates, audiences, and journey logic.