TandemWay

Senior Mobile Developer 

Intro 

We are looking for a Senior Mobile Developer to join our team working with a Silicon Valley startup on a mission-critical AI assistant for military vehicles. This product is already actively deployed and used by the Ukrainian Army to support their operations. We are committed to this mission and provide our help to the UA army for free. 

You will take ownership of our mobile strategy, helping us transition from a prototype to a robust, field-ready solution that operates in disconnected environments. 

The Challenge 

Our current prototype is built in Kotlin (Android) with native C++ modules to handle on-device LLM inference, which is the core feature of the product. The application must be fully functional offline. 

We are at a crossroads and need an expert to determine the future technology stack: whether to continue with native development (expanding to iOS) or migrate to a cross-platform framework like React Native or Flutter. You will drive this decision and lead the implementation. 

Technologies 

• Current: Android (Kotlin), C++ (NDK/JNI) 
• Potential: iOS (Swift), React Native, Flutter 
• Core: On-device LLM Inference, Offline-first architecture, Low-latency performance 

Responsibilities 

• Analyze the existing Kotlin/C++ prototype and performance requirements. 
• Lead the architectural decision-making process (Native vs. Cross-platform) based on performance, maintainability, and AI integration needs. 
• Design and implement the production-grade mobile application. 
• Integrate and optimize on-device LLM inference engines (interacting with C++ layers). 
• Ensure the application is stable, secure, and responsive in offline, resource-constrained environments. 
• Collaborate with AI engineers to optimize model delivery and execution on mobile devices. 

Requirements 

• Deep expertise in mobile application development (both Android and iOS). 
• Experience integrating native libraries into mobile applications. 
• Experience with or strong understanding of cross-platform frameworks (React Native or Flutter) to objectively evaluate trade-offs. 
• Knowledge of on-device ML/AI (running models locally) is a significant plus. 
• Strong system design skills, particularly for offline-first architectures. 
• Mission-driven mindset with a focus on reliability and user experience. 

Senior React Developer 

Intro 

We are looking for a Senior React Developer to join our team working with a Silicon Valley startup on a mission-critical AI assistant for military vehicles. This product is already actively deployed and used by the Ukrainian Army to support their operations. We are committed to this mission and provide our help to the UA army for free. 

You will drive the development of our web interfaces, ensuring high performance, responsiveness, and reliability for a system that operates in critical environments. 

Technologies 

• Frontend: React, Vite, Tailwind CSS, TypeScript, Playwright 
• Backend: REST API in Python (FastAPI), Supabase 
• Infrastructure: Cloud-native platform on Kubernetes with CI/CD 
• AI/LLM: Integration with AI agents and RAG workflows 

Responsibilities 

• Design and implement complex, responsive user interfaces using React and TypeScript. 
• Optimize application performance for low-latency and high-reliability environments. 
• Collaborate with the Backend and AI teams to integrate real-time data and AI-driven features. 
• Establish frontend engineering standards, code quality, and testing practices. 
• Mentor other engineers and contribute to architectural decisions on the client side. 
• Ensure the application is robust and user-friendly for operators in the field. 

Requirements 

• Deep experience building complex web applications with React and TypeScript. 
• Strong understanding of modern frontend build tools, state management, and performance optimization techniques. 
• Solid understanding of RESTful APIs. 
• Mission-driven mindset with a focus on reliability and user experience. 
• Ability to work independently and collaborate effectively in a fast-paced environment.