Software Engineer, Kotlin & Android Specialist
Saul Cintero
I'm a passionate and creative professional with over 20 years of experience, 12 of them in mobile. I help companies build robust, scalable, and elegant applications that truly make an impact.
About me
I'm a Senior Android Engineer specialized in Kotlin and Jetpack Compose, with a strong focus on clean architecture and maintainable design.
What I enjoy most is turning complex ideas into simple, well-crafted products that people love to use. I’m passionate about learning, mentoring, and pushing the boundaries of what mobile experiences can be.
Lately, I’ve been expanding my expertise into Kotlin Multiplatform, aiming to build cohesive, high-quality solutions that bridge Android, iOS, and beyond.
If you’re curious to see what I’ve been working on, here are some links you might find interesting 👇
Work experience
Mobile & DevOps Engineer
Hiberus - Zaragoza, Spain
2021 - Present
I’ve led Android development across multiple sectors (finance, public, media, entertainment and retail) helping companies deliver stable, scalable mobile solutions used by thousands of users every day.
In finance, I refactored a legacy app to modern Android architecture standards, introducing dependency injection, ViewModels, and native navigation. The result was a cleaner, more modular codebase and faster delivery cycles. I also implemented testing strategies that strengthened reliability and migrated the CI/CD pipelines to GitLab CI with Fastlane on Docker, cutting deployment times by over half.
For a public sector client, I took ownership of a greenfield project, gathering requirements directly from the Product Owner and coordinating backend and iOS efforts. Despite starting from zero context, we delivered a fully functional system on schedule.
In media, I focused on stabilization, eliminating persistent legacy crashes and bringing the error rate to nearly zero in an app with over 100,000 downloads.
Within entertainment & leisure, I worked on an app managing over €500K in annual operations, achieving 0% data loss and improving responsiveness by 15% in low-connectivity environments.
Finally, in retail and consumer services, I introduced an organized Git workflow, fixed complex background notification issues affecting devices like Xiaomi, strengthened app security with two-factor authentication & card tokenization and migrated the entire project to Android API 35, refactoring GraphQL and AAB builds to align with the latest standards.
Software Engineer
ALCAD Electronics - Irun, Spain
2020 - 2021
I worked on projects that blended modern web development and real-time AI systems.
I migrated an internal management platform from ActionScript 3 to TypeScript, applying Google’s Material Design to create a cleaner and more consistent interface.
I developed a Linux daemon in C++ that processed video streams from 20+ IP cameras per Intel NUC, applying AI-based facial recognition in collaboration with a security research firm. This required tight memory optimization and efficient use of resources within Dockerized environments. A genuine challenge in edge computing.
CTO & Co-Founder
Kinendu - Irun, Spain
2017 - 2023
I was responsible for defining the technical direction of the company, from system architecture and AWS infrastructure to product delivery and investor presentations.
I designed and implemented two REST APIs (internal and public), led the development of our Android app and coordinated cross-platform teams for iOS and Web. I also handled UI/UX consistency, database scalability, and automated backups, ensuring reliability across the entire stack.
My role combined strategy and hands-on coding: Managing infrastructure, leading technical decisions, and helping the business grow through clear technical communication with partners and investors.
Software Developer & Network Administrator
TransNatur Norte - Irun, Spain
2002 - 2019
My early years at TransNatur gave me a broad technical foundation: From systems administration to full-stack development.
I built native Android and iOS apps for real-time logistics tracking and proof-of-delivery, enabling faster operations and better visibility. I also developed custom integrations with third-party platforms, virtualized internal services like Active Directory and CRM, and implemented organization-wide security and backup policies that strengthened data integrity and uptime.
It was a long journey that transitioned me from infrastructure and IT management into the world of software engineering, where my focus eventually shifted fully to mobile development.
Featured Projects
Explore some of my recent work and creative solutions.
MeteoMate:
Weather forecast with AI-powered outfit suggestions
Description:
I developed a weather app with the goal of handling several different data sources, improving my testing skills, learning how to use design tools like Figma and with growth potential (such as porting it to Android TV, Android Auto or Android XR).
Role:
I carried out the entire end-to-end process, from the conception of the idea to its execution and deployment.
Skills
Discover the proficiencies that allow me to to create and mantain innovative mobile solutions
Kotlin
Main programming language for Android development for over 5 years, focusing on clean and scalable architecture.
Android SDK
Proficient in developing robust and maintainable Android applications using modern tools and best practices.
Jetpack Compose
Experienced in building modern UIs with Compose, applying Material Design and responsive layouts.
UI/UX Design Competence
Understanding of Material Design and accessibility principles to create user-centered experiences across devices.
Continuous Learning and Adaptability
Embracing new technologies and methodologies to improve development efficiency and product quality.
Results-oriented
Analytical mindset and strong problem-solving skills, balancing technical precision with user impact.
Get in touch
Send me a message and I'll follow up as soon as posible. Let's talk!