Looks like you have JavaScript disabled. For the full Twine experience, you will need to re-enable it.

I am a Senior iOS Engineer & SDK Architect with 12+ years of experience building apps and frameworks at Uber, Zalando, Lotto24, and Storyblok. Specialized in Swift, SwiftUI, SDK design, and scalable app architectures, with a proven track record of delivering products used by 10M+ users worldwide. Known for reducing integration times by 60%, boosting revenue through faster checkouts, and raising engagement by 20%+. Passionate about developer advocacy, mentoring, and cross-platform consistency.…I am a Senior iOS Engineer & SDK Architect with 12+ years of experience building apps and frameworks at Uber, Zalando, Lotto24, and Storyblok. Specialized in Swift, SwiftUI, SDK design, and scalable app architectures, with a proven track record of delivering products used by 10M+ users worldwide. Known for reducing integration times by 60%, boosting revenue through faster checkouts, and raising engagement by 20%+. Passionate about developer advocacy, mentoring, and cross-platform consistency.

Amit Sen





I am a Senior iOS Engineer & SDK Architect with 12+ years of experience building apps and frameworks at Uber, Zalando, Lotto24, and Storyblok. Specialized in Swift, SwiftUI, SDK design, and scalable app architectures, with a proven track record of delivering products used by 10M+ users worldwide. Known for reducing integration times by 60%, boosting revenue through faster checkouts, and raising engagement by 20%+. Passionate about developer advocacy, mentoring, and cross-platform consistency.…I am a Senior iOS Engineer & SDK Architect with 12+ years of experience building apps and frameworks at Uber, Zalando, Lotto24, and Storyblok. Specialized in Swift, SwiftUI, SDK design, and scalable app architectures, with a proven track record of delivering products used by 10M+ users worldwide. Known for reducing integration times by 60%, boosting revenue through faster checkouts, and raising engagement by 20%+. Passionate about developer advocacy, mentoring, and cross-platform consistency.

Available to hire

I am a Senior iOS Engineer & SDK Architect with 12+ years of experience building apps and frameworks at Uber, Zalando, Lotto24, and Storyblok. Specialized in Swift, SwiftUI, SDK design, and scalable app architectures, with a proven track record of delivering products used by 10M+ users worldwide. Known for reducing integration times by 60%, boosting revenue through faster checkouts, and raising engagement by 20%+. Passionate about developer advocacy, mentoring, and cross-platform consistency.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

German

Beginner

Bengali

Fluent

Work Experience

Senior iOS Architect at Storyblok GmbH

July 1, 2024 - Present

Architected a modular SDK in Swift & SwiftUI, reducing integration complexity for 100+ client apps and boosting developer adoption. Streamlined API design, CocoaPods/Fastlane pipelines, and CI/CD automation, cutting integration time by 60%. Launched 3 SwiftUI developer tools and 2 sample apps, increasing onboarding efficiency by 20% MoM. Authored 100+ pages of technical documentation, decreasing support tickets by 40% and enabling self-service adoption. Collaborated with backend & Android teams to synchronize GraphQL/REST APIs for cross-platform consistency.

Senior iOS Engineer at Lotto24 AG

June 1, 2024 - September 11, 2025

Migrated 80% of UIKit screens to SwiftUI, improving UI test stability by 35% and enhancing customer experience. Refactored legacy Objective-C → Swift (MVVM), reducing technical debt by 70% and enabling scalable feature delivery. Delivered widgets for 200K+ weekly users, driving 18% engagement growth and direct monetization gains. Improved unit test coverage to 60%, cutting production bugs and lowering costs. Integrated REST APIs & Firebase analytics to power data-driven product decisions and revenue optimization.

Senior iOS Engineer at Zalando SE

March 1, 2020 - September 11, 2025

Developed a native Swift payment SDK processing 3M+ monthly transactions, cutting checkout latency by 15% and boosting revenue. Redesigned payment flows with SwiftUI/UIKit & Figma collaboration, increasing checkout conversions by 20%. Built reusable modules for shopping & rewards, accelerating feature rollout by 30% across multiple teams. Partnered with backend engineers to align on API contracts (REST & Swagger), ensuring reliability and scalability. Improved crash monitoring & observability, lowering crash rates and improving customer trust.

iOS Engineer at Champs21

July 1, 2014 - September 11, 2025

Built Classtune app used by 30K+ students across 200 schools, driving digital adoption in education. Implemented offline sync (Core Data) for 10K+ records, ensuring seamless use in low-connectivity regions. Developed secure local storage with encryption, preventing breaches and ensuring GDPR-style compliance. Maintained compatibility across 5 iOS versions + 12 devices, lowering maintenance overhead. Released fast-iteration features from analytics insights, improving retention by 20%.