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I am a seasoned iOS engineer specializing in Swift and Objective-C with over sixteen years of end-to-end experience in the feature development lifecycle, including ideation, design, architecture, implementation, testing, and release of production-level iOS applications. I also have three years of experience with Android development using Kotlin. I have many years of experience leading projects and developing features for high-profile clients. I am passionate about mobile technologies, code quality, and continuous learning, and I am eager to bring my expertise to architecting robust, scalable project solutions.…I am a seasoned iOS engineer specializing in Swift and Objective-C with over sixteen years of end-to-end experience in the feature development lifecycle, including ideation, design, architecture, implementation, testing, and release of production-level iOS applications. I also have three years of experience with Android development using Kotlin. I have many years of experience leading projects and developing features for high-profile clients. I am passionate about mobile technologies, code quality, and continuous learning, and I am eager to bring my expertise to architecting robust, scalable project solutions.

Brandon Mantzey

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I am a seasoned iOS engineer specializing in Swift and Objective-C with over sixteen years of end-to-end experience in the feature development lifecycle, including ideation, design, architecture, implementation, testing, and release of production-level iOS applications. I also have three years of experience with Android development using Kotlin. I have many years of experience leading projects and developing features for high-profile clients. I am passionate about mobile technologies, code quality, and continuous learning, and I am eager to bring my expertise to architecting robust, scalable project solutions.…I am a seasoned iOS engineer specializing in Swift and Objective-C with over sixteen years of end-to-end experience in the feature development lifecycle, including ideation, design, architecture, implementation, testing, and release of production-level iOS applications. I also have three years of experience with Android development using Kotlin. I have many years of experience leading projects and developing features for high-profile clients. I am passionate about mobile technologies, code quality, and continuous learning, and I am eager to bring my expertise to architecting robust, scalable project solutions.

Available to hire

I am a seasoned iOS engineer specializing in Swift and Objective-C with over sixteen years of end-to-end experience in the feature development lifecycle, including ideation, design, architecture, implementation, testing, and release of production-level iOS applications. I also have three years of experience with Android development using Kotlin. I have many years of experience leading projects and developing features for high-profile clients. I am passionate about mobile technologies, code quality, and continuous learning, and I am eager to bring my expertise to architecting robust, scalable project solutions.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Lead Technical Consultant at Perficient

January 31, 2024 - August 27, 2025

Developed and maintained iOS applications for major clients using Swift and Objective-C. Implemented a flexible and customizable system for TD Ameritrade customers to manage their migration to the Schwab Mobile app, supporting over 13.5 million users. Utilized XCTest for code quality assurance. Contributed to FlutterFlow internal projects and supported Android development with Kotlin, ensuring feature parity with iOS projects.

Senior Software Developer at Garmin International

October 31, 2021 - August 27, 2025

Significant contributor to the launch of the Garmin Dive app, utilizing MVVM architecture. Integrated Bluetooth, GraphQL, and MapKit technologies. Collaborated with multiple internal teams on features for Garmin Golf, Garmin Jr., and Garmin Connect. Developed and maintained iOS and Android SDKs tailored for diverse team integration needs. Participated in Agile discussions to define technical requirements and product planning.

Senior Software Engineer at Lindsay (formerly Elecsys)

October 31, 2019 - August 27, 2025

Rewrote flagship iOS application using Clean Swift Architecture, rapidly developing features based on evolving business requirements. Worked directly with API developers to clarify business needs and optimize endpoints. Led production and publishing of new Android app, managing a small team. Collaborated proactively with product owners and managers to deliver significant new feature sets praised by management and recognized by the company CEO.

Senior Software Engineer (Contract) at GE Power and Water

February 28, 2017 - August 27, 2025

Contributed significantly as a senior developer to the development of an internal maintenance tracking iOS application written in Swift, integrating RESTful APIs and complex UI adhering to Apple's Human Interface Guidelines. Collaborated with Apple consultants on enhancements and worked efficiently within Agile teams to achieve project milestones.

Software Developer (Contract) at VML

February 28, 2016 - August 27, 2025

Developed and implemented features for LegalShield and Hills Pet Nutrition apps using Swift and Clean Swift Architecture. Contributed to QuikTrip app development. Collaborated in an Agile team environment, delivering client-specific features to satisfaction.

Lead iOS Software Engineer at Exploria

August 31, 2015 - August 27, 2025

Managed full development lifecycle for custom-branded iPad projects for pharmaceutical clients. Developed a system using 3DES encryption for sensitive data bundled with apps, including a macOS utility for secure data encryption. Maintained and updated multiple Objective-C iPad applications, some with legacy memory management.

Lead Technical Consultant at Perficient

January 31, 2024 - August 27, 2025

Developed and maintained iOS applications for major clients using Swift and Objective-C. Implemented a flexible and customizable system advising TD Ameritrade customers on important dates for their transition to the Schwab Mobile app, enabling the migration of over 13.5 million users. Utilized XCTest to verify code quality and minimize defects. Contributed to an internal FlutterFlow project and collaborated on Android development features using Kotlin.

Senior Software Developer at Garmin International

October 31, 2021 - August 27, 2025

Significant contributor to the launch of the Garmin Dive app, which utilizes MVVM architecture. Integrated technologies such as Bluetooth, GraphQL, and MapKit. Collaborated with multiple internal teams on features for Garmin Golf, Garmin Jr., and Garmin Connect. Developed and maintained iOS and Android SDKs for internal team use, adapting SDKs to diverse integration needs. Participated in Agile product planning and technical discussions.

Senior Software Engineer at Lindsay (formerly Elecsys)

October 31, 2019 - August 27, 2025

Rewrote the flagship iOS application using Clean Swift Architecture, rapidly developing features based on evolving business requirements. Worked directly with API developers to clarify business requirements and optimize endpoint responses. Led production and publishing of a new Android app, managing a small team. Fostered proactive collaboration with product owners and managers, delivering feature sets praised by managers and recognized by the company CEO.

Senior Software Engineer (Contract) at GE Power and Water

February 28, 2017 - August 27, 2025

Contributed significantly as a senior developer to a large internal maintenance tracking iOS app written in Swift that integrated RESTful APIs with complex UI in adherence to Apple’s Human Interface Guidelines. Collaborated with Apple consultants to explore enhancements and worked within Agile teams to deliver project milestones efficiently.

Software Developer (Contract) at VML

February 29, 2016 - August 27, 2025

Developed and implemented features for LegalShield and Hills Pet Nutrition apps using Swift and Clean Swift Architecture. Contributed to the development of QuikTrip app. Worked as part of an Agile team to communicate with clients and deliver features to their specifications and satisfaction.

Lead iOS Software Engineer at Exploria

August 31, 2015 - August 27, 2025

Managed full development lifecycle for custom-branded iPad projects for pharmaceutical clients. Created a system using 3DES to encrypt sensitive data bundled with the app, including a macOS tool and iOS implementation for encryption and decryption. Maintained and updated multiple legacy Objective-C iPad applications and developed a macOS utility for secure data encryption.

Lead Technical Consultant at Perficient

January 31, 2024 - August 27, 2025

Developed and maintained iOS applications for major clients using Swift and Objective-C. Implemented a flexible and customizable system advising TD Ameritrade customers about important dates related to their transition to the Schwab Mobile app, enabling migration of over 13.5 million users. Utilized XCTest to verify code quality and minimize defects. Contributed to an internal FlutterFlow project and supported the Android development team with Kotlin features in parity with the iOS project.

Senior Software Developer at Garmin International

October 31, 2021 - August 27, 2025

Significant contributor to the launch of the Garmin Dive app using MVVM architecture. Integrated Bluetooth, GraphQL, and MapKit technologies. Collaborated with multiple internal teams to support features for Garmin Golf, Garmin Jr., and Garmin Connect. Developed and maintained iOS and Android SDKs used internally across teams, adapting SDKs to diverse integration needs. Participated in Agile discussions to define technical requirements and product planning with technical estimates.

Senior Software Engineer at Lindsay (formerly Elecsys)

October 31, 2019 - August 27, 2025

Rewrote the flagship iOS application using Clean Swift Architecture, rapidly developing features based on evolving business requirements. Worked directly with API developers to clarify business needs and optimize endpoints. Led production and publishing of a new Android app with a small team. Proactively collaborated with product owners and managers, resulting in rapid feature development praised by managers and recognized by the company CEO.

Senior Software Engineer (Contract) at GE Power and Water

February 28, 2017 - August 27, 2025

Contributed significantly to the development of an internal maintenance tracking iOS application written in Swift, integrating RESTful APIs and complex UI adhering to Apple’s Human Interface Guidelines. Collaborated with Apple consultants on enhancements and worked within Agile teams to deliver project milestones efficiently.

Software Developer (Contract) at VML

February 29, 2016 - August 27, 2025

Developed and implemented features for LegalShield and Hills Pet Nutrition apps using Swift and Clean Swift Architecture. Contributed to the development of QuikTrip. Worked as part of an Agile team to communicate with clients and deliver features to specification and satisfaction.

Lead iOS Software Engineer at Exploria

August 31, 2015 - August 27, 2025

Managed full development lifecycle for custom-branded iPad projects for pharmaceutical clients. Created a system using 3DES for encrypting sensitive data bundled with apps, including macOS tool and iOS app implementation. Maintained and updated multiple Objective-C iPad applications, including legacy memory management, and developed a macOS utility for secure data encryption.