08/11/2026 updated

**** ******** ****
100 % available

Freelance Mobile Developer & Consultant (iOS & Android)

Meppel, Netherlands
Only remote
Windesheim University of Applied Sciences (2010-2014)
Meppel, Netherlands
Only remote
Windesheim University of Applied Sciences (2010-2014)

Profile attachments

Jeffrey CV - silfonia 2026 Updated.pdf

IOS Applications
Mobile Development (iOS & Android)
Over twelve years of experience in native mobile development for both iOS and Android platforms. Expertise in Swift, Objective-C, Kotlin, and Java, as well as modern frameworks such as SwiftUI, UIKit, and Jetpack Compose.

UI & UX Design
Strong focus on simplicity, clean user interfaces, and excellent user experience. Proven track record of implementing UX redesigns, accessibility features, and mobile-first design approaches across multiple client projects.

Clean Architecture & API Design
Deep expertise in clean architecture principles, backend architecture, API design, and GraphQL. Experience with architectural patterns such as MVVM, MVC, VIPER, Clean Swift, and protocol-oriented programming.

Enterprise Infrastructure & Firebase
Experience with enterprise-level infrastructure, Firebase integrations, and security best practices including OWASP guidelines.

Continuous Integration & Delivery
Proficiency in CI/CD pipelines, Git Flow, Agile and Scrum methodologies, and mobile testing including unit testing and snapshot testing.

Performance Optimization
Hands-on experience with CPU, GPU, and memory optimization, as well as battery usage improvements for mobile applications.

Frameworks & APIs
Extensive use of iOS frameworks including UIKit, SwiftUI, CarKit, WidgetKit, StoreKit, and AppIntents, as well as Android libraries such as Hilt/Dagger, Retrofit, and Room.

Leadership & Team Coaching
Experience in leading mobile teams, mentoring junior engineers, personal coaching, and acting as mobile development consultant for enterprise-level customers.

Concurrency & Async Programming
Skilled in modern concurrency approaches including Async/Await, Combine, Actors on iOS, and Coroutines on Android.

Experience

Professional experience10+ years
Freelancer since2022

Languages

EnglishFluentDutchNative speaker

Project history

Freelance Mobile Developer

Action
Built shared design-system components for iOS and Android (SwiftUI and Jetpack Compose). Refactored legacy UI to modern SwiftUI, supported the app expansion into 5 countries, and significantly improved test coverage and app stability.

Freelance Developer

JSchonewille & Silfonia
Android & iOS innovation and tooling. Advising customers about their mobile strategy, improving end consumer user experience, implementing clean architecture, and building mobile apps.

Freelance Mobile Developer

NPO
Developed the NPO Luister app based on the latest innovations and UX guidelines. Implemented Car Play, Widgets, and Accessibility features.

Mobile Lead

Move
Android & iOS innovation and tooling. Mobile development consultant for enterprise level customers, mapping out company mobile strategy, and HR and coaching responsibilities.

Freelance Mobile Developer

NPO
Developed a new mobile app (NPO ZAPP) for kids with social media 2022 UI and feeling, and custom animations and UX for the target audience.

Lead iOS

Move
iOS lead role within Move4Mobile. Personal coaching and mapping out company strategy for iOS.

Freelance Mobile Developer

OHRA
Improved overall UX of native app, implemented clean architecture, improved overall IT landscape and architecture, future roadmap creation, and multi OAuth implementation.

Mobile Developer

Move
Advising customers about their mobile strategy, improving customer IT infrastructure, improving end consumer user experience, and implementing and teaching clean architecture.

Freelance Mobile Developer

Timing
Implemented new features, advanced analytics and user tracking, CPU & GPU & battery usage improvements, advanced animations, and mobile & web interactivity.

Freelance Mobile Developer

Rabobank
Implemented new features for Rabobank Smartpin, advanced analytics and user tracking, new clean architecture, CPU & GPU & battery usage improvements, and Bluetooth SDK integration with pin device.

Freelance Mobile Developer

Cooperatie Unive U.A
Instructed on a mobile first approach, web & mobile interactivity, improved overall IT architecture, UX rework of native app, and implemented clean architecture.

Freelance Mobile Developer

Plus Retail B.V
Clean architecture implementation, increased team velocity by 100%, improved overall IT landscape and architecture, implemented advanced monitoring, rich push notifications, loyalty features and more.

Freelance Mobile Developer

TVGids.nl
Implemented redesign focused on UX, mobile backend design, added UX friendly advertisements, focus on speed and simplicity, analytics and AB testing.

Freelance Mobile Developer

Intergas verwarming
Implemented redesign focused on UX, delivered a smooth experience while working with legacy backend systems, and worked with external systems like boilers, thermostats, etc.

Freelance Mobile Developer

ASR Holding B.V
Developed an iPad app for shop owners and an iPhone app for customers (Mijn LRC). Created a middleware layer combining services from multiple vendors and delivered an overall great Loyalty experience.

Freelance Mobile Developer

Timing Uitzendteam BV
Cleaned up codebase and architecture, focused on helping end users with daily usage of the app, and advised the API team on mobile friendliness of their APIs.

Freelance Mobile Developer

ASSET Rail BV
Created a new app that helps contractors save paperwork, maintained close contact with end users, and translated customer wishes into requirements and functionalities.

Freelance Mobile Developer

Tellow B.V
Created a functioning backend, iOS app MVP for a moonshot concept, chat based UX, banking calculations, and mobile first design.

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