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

I am a Senior mobile and web application developer with 12 years of experience mastering leading technologies including React Native, JavaScript, Swift, Kotlin, Node.js, Go, and Express.js. Throughout my career, I have consistently delivered high-quality applications that exceed client expectations, leveraging my expertise in Redux, TypeScript, and AWS. I am passionate about continuous improvement and innovation in software development, with strong skills in cross-platform development focusing on mobile and web UI/UX architecture. I also have proven proficiency in performance optimization for both front-end and back-end systems and experience with various databases. I am authorized to work in the US for any employer and eager to bring my skills and enthusiasm to a dynamic team.…I am a Senior mobile and web application developer with 12 years of experience mastering leading technologies including React Native, JavaScript, Swift, Kotlin, Node.js, Go, and Express.js. Throughout my career, I have consistently delivered high-quality applications that exceed client expectations, leveraging my expertise in Redux, TypeScript, and AWS. I am passionate about continuous improvement and innovation in software development, with strong skills in cross-platform development focusing on mobile and web UI/UX architecture. I also have proven proficiency in performance optimization for both front-end and back-end systems and experience with various databases. I am authorized to work in the US for any employer and eager to bring my skills and enthusiasm to a dynamic team.

Kacper Markowski

Full Stack Developer, Web Developer, App Developer, +1





I am a Senior mobile and web application developer with 12 years of experience mastering leading technologies including React Native, JavaScript, Swift, Kotlin, Node.js, Go, and Express.js. Throughout my career, I have consistently delivered high-quality applications that exceed client expectations, leveraging my expertise in Redux, TypeScript, and AWS. I am passionate about continuous improvement and innovation in software development, with strong skills in cross-platform development focusing on mobile and web UI/UX architecture. I also have proven proficiency in performance optimization for both front-end and back-end systems and experience with various databases. I am authorized to work in the US for any employer and eager to bring my skills and enthusiasm to a dynamic team.…I am a Senior mobile and web application developer with 12 years of experience mastering leading technologies including React Native, JavaScript, Swift, Kotlin, Node.js, Go, and Express.js. Throughout my career, I have consistently delivered high-quality applications that exceed client expectations, leveraging my expertise in Redux, TypeScript, and AWS. I am passionate about continuous improvement and innovation in software development, with strong skills in cross-platform development focusing on mobile and web UI/UX architecture. I also have proven proficiency in performance optimization for both front-end and back-end systems and experience with various databases. I am authorized to work in the US for any employer and eager to bring my skills and enthusiasm to a dynamic team.

Available to hire

I am a Senior mobile and web application developer with 12 years of experience mastering leading technologies including React Native, JavaScript, Swift, Kotlin, Node.js, Go, and Express.js. Throughout my career, I have consistently delivered high-quality applications that exceed client expectations, leveraging my expertise in Redux, TypeScript, and AWS.

I am passionate about continuous improvement and innovation in software development, with strong skills in cross-platform development focusing on mobile and web UI/UX architecture. I also have proven proficiency in performance optimization for both front-end and back-end systems and experience with various databases. I am authorized to work in the US for any employer and eager to bring my skills and enthusiasm to a dynamic team.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Beginner

Work Experience

Senior Full Stack Engineer at SoftTeco

June 1, 2025 - August 13, 2025

Worked on the US’s leading boat rental platform across mobile (iOS & Android) and web. Built new features, maintained existing ones, and improved performance using React Native, Next.js, Ruby on Rails, JavaScript, TypeScript, Swift, and Kotlin. Developed multiple mobile app features end-to-end, from UI to API integration. Utilized Xcode, Android Studio, Gradle, Flipper, and React Native Debugger in day-to-day development. Built mobile features in bare React Native with Redux for state management, Axios for API calls, JWT for authentication, and Jest for unit tests. Created and updated backend REST APIs in Ruby on Rails. Collaborated closely with designers, PMs, QA, and other developers in Agile sprints. Provided code reviews and feedback during cross-team discussions.

Senior Software Engineer at Accenture

May 1, 2022 - August 13, 2025

Contributed to multiple web and mobile products in a cross-functional team, focusing on performance, maintainability, and smooth user experience. Migrated core mobile features from Flutter to React Native and added new capabilities. Built front-end features with React Native and integrated Firebase for authentication, storage, and push notifications. Implemented custom Google Maps overlays, routes, and interactive markers. Used Redux for state management on mobile and web. Integrated OAuth authentication flows and set up push notifications via APNS and FCM. Delivered features closely coordinating with QA, designers, and backend teams.

Software Engineer at Endava

June 1, 2018 - August 13, 2025

Worked on web and mobile applications for multiple clients, handling new development and ongoing support. Built a dealer portal web app with image/tile-based layout using HTML5, CSS3, JavaScript, Bootstrap, AngularJS, and ReactJS. Developed iOS apps using MVC architecture and integrated third-party SDKs like Stripe and SDWebImage. Connected iOS apps to Go-based backend services with monitoring via Prometheus and OpenTelemetry. Created CI/CD pipelines with automated unit tests and E2E tests. Managed deployments to staging and production, plus mobile releases to TestFlight, App Store, and Google Play. Added and maintained AWS Amplify + Node.js APIs for mobile features like data read/write.