Vermillion is the trusted technical partner for subscription app operators looking to develop and expand their products. We collaborate with growth marketers, portfolio creators, and independent app founders who are knowledgeable about users and revenue yet require a reliable senior engineering team for the long term rather than just a few months. Our focus is on React Native applications, with extensive knowledge in subscription monetization, paywall optimization, and the RevenueCat/Superwall technology stack. Our longest-standing client partnership has lasted over four years, during which we became their complete engineering support as they grew to achieve $750K per month in subscription revenue. Our Services Include: development of React Native mobile applications, strategies and implementations for subscription monetization, paywall A/B testing and optimization, architecture design for scalability and acquisition readiness, and providing fractional CTO advisory services for technical decisions. Our Clients Are: subscription app operators and portfolio builders, growth marketers creating app-based businesses, independent app founders scaling beyond product-market fit, and companies preparing for acquisition or due diligence. Reasons for Client Loyalty: we have experience with over 50 subscription apps and understand what drives conversion. We've navigated technical due diligence and know what potential acquirers seek. Our clients remain with us because we are not merely a project-based team; we are the engineering team they can count on indefinitely. Additionally, our clients have collectively raised more than $27 million in funding. Vermillion was founded by Ken Vermeille, a developer with over 15 years of full-stack experience and significant expertise in mobile monetization.