Meet the Experts
Our global community of RevenueCat Experts helping developers succeed with in-app subscriptions and monetization.
Expert Directory
Paulo Coutinho
Engineering/Software Development
Ubook
I’m a product-minded engineer and technical leader focused on mobile, architecture, and execution. I work hands-on across the full lifecycle of digital products—from technical direction to delivery—with strong experience in iOS and Android using Swift and Kotlin, and C++ when native performance and low-level control matter. My work also covers APIs, integrations, infrastructure, performance, and distribution. As Co-founder of Ubook, I led mobile, architecture, and performance across one of Brazil’s leading audiobook platforms. I helped build the product from its early stages through growth, international expansion, and a funding round that supported scale. It was a hands-on experience in building a real product company with long-term technical and product responsibility. I also maintain open source libraries and long-term engineering projects across native stacks, web tooling, and AI-related systems, applying the same discipline I bring to production code: clear architecture, sustainable maintenance, and practical performance. Alongside product work, I build and publish my own apps and games with full ownership across architecture, development, and distribution—reflecting my ability to build, lead, and ship software end to end with autonomy, technical depth, and product focus.
Christian Krueger
Information Technology (IT)
Solo Developer
I'm Chris Krueger, a Berlin-based solo developer with over 14 years of software experience. I started my career in Java enterprise development before transitioning into mobile — growing from Android Engineer to Android Architect at KAYAK. Today I independently build and ship a growing portfolio of mobile apps using Kotlin Multiplatform — including Moviebase, ReSubs, and Momental. My focus is on scaling each app sustainably while continuously expanding the portfolio, applying everything I've learned from large-scale engineering to the challenges of indie development. Passionate about developing polished, user-centric products, I regularly share my learnings around app monetization, RevenueCat, Kotlin Multiplatform, and indie growth — on Twitter and in the wider developer community.