Oscar
From Colombia (UTC-5)
Oscar – Kotlin, Android, Java
Oscar is a mobile engineer focused on native Android with Kotlin and Jetpack Compose, and he also ships iOS in SwiftUI. On a clinical communication app, he owned real-time video and audio integrations, refactored both codebases, and raised automated test coverage from under 10% to over 70%.
13 years of commercial experience in
Main technologies
Additional skills
Direct hire
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Let’s get started today!Experience Highlights
Mobile Engineer
A language-access platform that connects clinical staff to professional interpreters on demand.




- Built and shipped features concurrently across native Android and iOS applications using Kotlin, Jetpack Compose, Swift, and SwiftUI.
- Owned real-time audio and video integrations with Twilio and Amazon Chime.
- Refactored both codebases to eliminate duplication and improve release stability.
- Increased automated test coverage from below 10% to more than 70%.
- Established CircleCI pipelines to make releases predictable for a point-of-care product.
Mobile Engineer
A delivery application where couriers and customers coordinate in real time during an active order.



- Modernized a legacy Android application supporting a medical delivery platform.
- Developed features that improved performance, stability, and maintainability.
- Introduced unit testing and CI/CD practices to reduce regressions.
- Expanded automated test coverage for a Kotlin and Jetpack Compose delivery application with real-time communication.
- Collaborated closely with QA and product teams to stabilize releases under tight deadlines.
Mobile Engineer
A native iOS payments SDK for an employee-benefits product operating in 31 countries, serving around 36 million consumers across 1.7 million merchants.



- Developed and maintained a native iOS SDK for card digitization and in-app payments.
- Supported country engineering teams integrating the SDK into their consumer applications.
- Diagnosed and resolved integration issues within applications outside direct control.
- Maintained strict backward compatibility across versions used by multiple independent apps.
- Delivered secure, high-quality software aligned with regulated fintech standards.
Mobile Engineer
A digital payments platform used by banks and card issuers for tokenisation, card digitisation and wallet provisioning to Apple Pay, Google Pay and Samsung Pay, across roughly 300 million active cards.


- Led digital-payment development for fintech partners across Latin America.
- Built native iOS and Android plugins and SDKs for third-party issuer applications.
- Implemented card digitization and wallet provisioning flows for Apple Pay, Google Pay, and Samsung Pay.
- Used NFC, Android Keystore, and StrongBox to secure payment credentials.
- Delivered payment-critical code for applications outside the team’s ownership and release control.
Mobile Engineer
A clinical research application used to track cognitive and motor decline in study participants for a national health institute.
- Developed native iOS and Android applications for a clinical research protocol.
- Implemented offline-first data capture with Core Data to preserve sessions during connectivity loss.
- Integrated cardiac monitoring data from Apple Watch and Wear OS.
- Added Firebase Analytics and Crashlytics for usage insights and crash reporting.
Founder & Mobile Engineer
Interactive applications, games and multimedia experiences built for global consumer brands and creative agencies, much of it for live events — software that runs at a fixed moment in front of an audience, with no possibility of shipping a fix.
- Built interactive applications, games, and multimedia experiences for Sony Music, Huawei, McCann, Ogilvy & Mather, and Banco de Bogotá.
- Delivered projects end-to-end, from initial scoping and proposals through development and launch.
- Developed software for live events where reliability at a fixed time was essential.
- Managed client engagements, proposals, project scope, and delivery as the company founder.