Mark James
From: United States of America
Location: Lockbourne, US
On Useme since 3 October 2025
About me
Experienced Mobile & Web Developer | Kotlin & Android | Full-stack Developer |Blockchain & Web3 Developer | Smart Contract Audit Expert
I am an experienced Blockchain Full-stack developer specializing in Web3 and modern Android development. I build scalable, high-performance webs & mobile applications with a strong focus on clean architecture, maintainable code, and great user experience.
My expertise includes NFT marketplace, presale support, web3 develop ,Android SDK, Jetpack components, Coroutines, Flow, MVVM/MVI architectures, REST APIs, and third-party integrations. I have hands-on experience optimizing app performance, improving stability, and collaborating closely with product and design teams to deliver reliable features from concept to release.
I value code quality, clear communication, and continuous learning, and I enjoy solving complex problems that turn business requirements into elegant mobile solutions.
Categories
CV / Résumé
Sep 2021 - Dec 2025
Senior Mobile & Web Developer (Freelance / Contrac
Self-Employed – United States (Remote)
Providing end-to-end mobile, web, and blockchain development services to startups, agencies, and enterprise clients. Architected and delivered Android apps using Kotlin and Jetpack Compose, supporting scalable and maintainable codebases.
Dec 2019 - Aug 2021
Senior Android Developer
Toptal (Contract)
Worked with US and international clients as a senior Android consultant on high-impact projects. Developed production Android applications using Kotlin, MVVM, Clean Architecture, and REST APIs.
Sep 2018 - Nov 2019
Full-Stack Developer
Intellectsoft
Contributed to enterprise-grade web and mobile solutions for fintech and healthcare clients. Developed backend services using Node.js and Spring Boot, and frontend interfaces with React.
Jun 2016 - Aug 2018
Mobile Application Developer
WillowTree
Built and maintained high-quality Android applications for consumer and enterprise brands. Implemented modern Android components, offline-first architecture, and API integrations.
May 2015 - May 2016
Junior Software Engineer
Cognizant Technology Solutions
Started professional career working on web and mobile application development projects. Assisted in backend development, database management, and API integration. Gained hands-on experience with Java, REST services, and Agile development practi
Portfolio
ETHGlobal is a community-driven organization that hosts global hackathons and events to bring developers together to learn, build, and innovate on the Ethereum blockchain and broader Web3 ecosystem.
Built a scalable full‑stack analytics dashboard using Python, Django, and AI/ML models to monitor live system performance. Integrated contextual AI modules that process data streams, implemented REST APIs and WebSocket layers, and managed DevOps.
Developed a full‑stack AI platform using Python, Django, and cutting‑edge generative video tools for image‑to‑video, face‑swap and lip‑sync workflows. Built backend APIs for media generation, integrated LLM and vision modules, and managed DevOps.
This project involved designing and implementing an AI-powered computer vision platform for enterprise use, focusing on facial recognition, object detection, and secure, scalable deployment.