Senior Full-Stack Mobile Developer / Founding Engineer — Part-Time

Company Description: GoProtoz – UI UX Design Studio is a leading UX/UI design company with operations in India, the USA, Germany, and Dubai. With over 10 years in the UX/UI design business, the studio has delivered more than 500 projects worldwide, supported by a team of over 100 in-house designers and developers. GoProtoz partners with a wide range of clients, from global brands like Sony, Nissan, ICICI, and Tata to high-growth startups. The company provides UX/UI design, UX research, web and mobile app design, and end-to-end web and mobile app development services. Its work spans multiple industries including e-commerce, edtech, IT, banking and fintech, healthcare, automotive, defense, media, energy, consumer goods, and hospitality.
Role Description This is a part-time, on-site Senior Full-Stack Mobile Developer role based in India. The Senior Full-Stack Mobile Developer will collaborate closely with UX/UI designers, product managers, and other developers to build and maintain high-quality mobile applications that align with GoProtoz’s design standards and client requirements. Daily responsibilities include architecting and implementing mobile app features, integrating front-end interfaces with back-end services and APIs, optimizing performance and security, and ensuring consistent cross-platform behavior. The role also involves reviewing code, mentoring junior developers, participating in technical discussions, and contributing to continuous improvement of development processes and tooling. The developer will work on projects across various industries, helping transform user-centered designs into robust, scalable mobile experiences.
Qualifications
Candidates should possess strong mobile development skills, such as proficiency in native (e.g., Android, iOS) and/or cross-platform frameworks (e.g., React Native, Flutter).
Candidates should possess solid front-end development skills, including expertise in JavaScript/TypeScript, modern frameworks, responsive design, and integration with UX/UI design systems.
Candidates should possess back-end development skills, such as experience with server-side languages, RESTful APIs, microservices, and database design (SQL/NoSQL).
Candidates should possess skills in application architecture and DevOps practices, including version control (Git), CI/CD pipelines, testing, and performance optimization.
Candidates should possess strong collaboration and communication skills, with the ability to work closely with designers, product stakeholders, and cross-functional teams.
Relevant experience in building production-ready mobile applications for diverse domains such as e-commerce, fintech, healthcare, or media is highly beneficial.
A bachelor’s degree in Computer Science, Engineering, or a related field, or equivalent practical experience, is preferred.
Demonstrated ability to mentor others, take ownership of complex technical challenges, and deliver high-quality code on schedule is expected for a senior-level role.
We are building an AI-powered personalized health care mobile application and are looking for a senior hands-on engineer to own the technical development of our MVP.
The initial objective is to launch the product with approximately 1,000 real users and establish an architecture that can scale as we validate and grow the product.
Responsibilities
* Build the mobile application using React Native + Expo + TypeScript
* Design Supabase/PostgreSQL backend architecture
* Implement authentication and secure user-data access
* Build modular personalization and recommendation logic
* Implement habit/activity logging and behavioural data capture
* Build push-notification workflows
* Integrate AI/LLM APIs where appropriate
* Implement analytics and admin capabilities
* Establish scalable application architecture
* Testing, performance, security and production deployment
* Google Play release
Skills
Must have: React Native, TypeScript, Expo, PostgreSQL, APIs, authentication, database architecture and production mobile deployment.
Preferred: Supabase, Firebase/FCM, OpenAI/Claude APIs, recommendation systems, personalization engines, PostHog/Mixpanel and AI-assisted development using Cursor/Claude Code.
Experience building health-tech, behavioural, recommendation or personalized consumer applications is a strong advantage.
Engagement:
Part-time: 15–20 hours/week
Initial duration: 3 months
Location: Remote / India preferred
Stage: MVP → 1,000-user validation → Scale
We are looking for someone who can operate like a founding engineer, not simply implement screens—someone capable of making architecture decisions, challenging assumptions and taking technical ownership of the product.

Work arrangement
No