Jesus T.

Need a senior Android developer who can take a mobile product from idea to release—or step into an existing codebase and move it forward with confidence? I’ve been building Android applications professionally since 2015. My core stack includes Kotlin, Jetpack Compose, Kotlin Multiplatform, Compose Multiplatform, and modern Android architecture. I can help whether you’re building a new mobile product, expanding an existing application, modernizing a legacy codebase, or preparing an app for production release. Here’s where I usually bring the most value: • Building native Android applications from scratch • Developing shared Android and iOS experiences with Kotlin and Compose Multiplatform • Shipping new features in existing Android products • Migrating legacy codebases from Java/XML to Kotlin and Jetpack Compose • Improving architecture, scalability, maintainability, and performance • Debugging complex lifecycle, background behavior, and stability issues • Integrating REST APIs, Firebase, payments, maps, NFC, and Google services • Preparing applications for testing, release, and Google Play submission I’ve worked across fintech, healthcare, retail, and internal enterprise products. My experience includes contributing to a fintech application with more than 500,000 active users and building a high-demand system designed to support over 400,000 users in a single day. I also use AI-assisted development workflows, including Codex, to accelerate implementation, refactoring, testing, and documentation. Architecture decisions, code review, security, maintainability, and release quality remain under my direct technical ownership. I work best with teams that communicate clearly, define priorities, and value quality alongside speed. I’m comfortable working independently, collaborating with technical stakeholders, and getting productive quickly in unfamiliar codebases. If you’re planning a new Android or Android/iOS product—or need senior help moving an existing application forward—send me a brief description of the product, current stack, and main technical challenge. I’ll tell you how I would approach it.