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I'm Douglas Mandarino, a Senior iOS Software Engineer with 10+ years of experience building high-performance mobile applications in Swift and Objective-C. I excel in iOS architecture, authentication systems, session management, and building shared libraries used across multiple apps. I enjoy tackling challenging problems and delivering robust, user-friendly experiences. I've collaborated with Apple internal teams as a contractor and led critical platform work at Uber. My expertise spans Swift Concurrency, SwiftUI, Combine, RxSwift, UIKit, GraphQL, and REST APIs, and I have contributed to open-source projects including the Apollo GraphQL Client.…I'm Douglas Mandarino, a Senior iOS Software Engineer with 10+ years of experience building high-performance mobile applications in Swift and Objective-C. I excel in iOS architecture, authentication systems, session management, and building shared libraries used across multiple apps. I enjoy tackling challenging problems and delivering robust, user-friendly experiences. I've collaborated with Apple internal teams as a contractor and led critical platform work at Uber. My expertise spans Swift Concurrency, SwiftUI, Combine, RxSwift, UIKit, GraphQL, and REST APIs, and I have contributed to open-source projects including the Apollo GraphQL Client.

Douglas Mandarino

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I'm Douglas Mandarino, a Senior iOS Software Engineer with 10+ years of experience building high-performance mobile applications in Swift and Objective-C. I excel in iOS architecture, authentication systems, session management, and building shared libraries used across multiple apps. I enjoy tackling challenging problems and delivering robust, user-friendly experiences. I've collaborated with Apple internal teams as a contractor and led critical platform work at Uber. My expertise spans Swift Concurrency, SwiftUI, Combine, RxSwift, UIKit, GraphQL, and REST APIs, and I have contributed to open-source projects including the Apollo GraphQL Client.…I'm Douglas Mandarino, a Senior iOS Software Engineer with 10+ years of experience building high-performance mobile applications in Swift and Objective-C. I excel in iOS architecture, authentication systems, session management, and building shared libraries used across multiple apps. I enjoy tackling challenging problems and delivering robust, user-friendly experiences. I've collaborated with Apple internal teams as a contractor and led critical platform work at Uber. My expertise spans Swift Concurrency, SwiftUI, Combine, RxSwift, UIKit, GraphQL, and REST APIs, and I have contributed to open-source projects including the Apollo GraphQL Client.

Available to hire

I’m Douglas Mandarino, a Senior iOS Software Engineer with 10+ years of experience building high-performance mobile applications in Swift and Objective-C. I excel in iOS architecture, authentication systems, session management, and building shared libraries used across multiple apps. I enjoy tackling challenging problems and delivering robust, user-friendly experiences.

I’ve collaborated with Apple internal teams as a contractor and led critical platform work at Uber. My expertise spans Swift Concurrency, SwiftUI, Combine, RxSwift, UIKit, GraphQL, and REST APIs, and I have contributed to open-source projects including the Apollo GraphQL Client.

Skills

Experience Level

Expert

Expert

Expert

Expert

Intermediate

Language

English

Fluent

Portuguese

Fluent

Work Experience

Senior iOS Software Engineer at Apple (GSSM) / Formula.Monks (Apple)

September 1, 2024 - Present

Collaborate directly within Apple’s GSSM internal team on iOS and macOS applications. Design and implement features focused on performance, reliability, and user experience. Maintain and evolve components while introducing modern Swift and SwiftUI patterns.

Senior iOS Software Engineer at Lumenalta (formerly Clevertech)

May 1, 2023 - September 1, 2024

Developed and maintained complex iOS applications for international clients. Designed scalable architectures and improved performance using modern Swift features.

Senior iOS Software Engineer — Session Management at Uber

January 1, 2021 - May 1, 2023

Led OAuth 2.0 refactoring into a shared authentication library used by 100% of app traffic. Implemented cross-app login and supported Postmates account integration.

iOS Software Engineer ® Senior iOS Software Engineer at Grupo Globo — Globoplay

September 1, 2018 - January 1, 2021

Progressed from iOS Engineer to Senior within the same team. Delivered Home Screen features and led the Live TV MVP on the Globoplay app. Led REST → GraphQL migration and contributed a PR to Apollo GraphQL Client.

iOS Software Engineer at OLX Brasil

October 1, 2016 - September 1, 2018

Worked on analytics, tracking, monetization, and A/B testing features.

iOS Developer — Intern at Apple Developer Academy

November 1, 2014 - October 1, 2016

Internship program; participated in multidisciplinary teams building iOS applications for Apple platforms.

Software Engineering Intern at TG4

April 1, 2014 - October 1, 2014

Contributed to .NET-based backend development for e-commerce systems.

Software Engineering Intern at Ideais

October 1, 2012 - April 1, 2014

Worked as a Java developer on backend APIs for large-scale B2W e-commerce projects.