Senior Fullstack Engineer - AI

Description:

About Us

We are Papaya. We believe in the power of play. We’re building the most exciting player community in the world - turning everyday moments into social tournaments and competitive banter. We are dreamers and doers who bring joy to millions. Now, we are looking for an innovative builder to revolutionize how we manage our games through AI.

About The Role

We are seeking a Senior Fullstack Engineer to lead the UI solution for our next-generation AI Calendar - an intelligent "Co-pilot" application that assists our LiveOps teams in managing game economies and events. This is a product-first engineering role. You will be architecting a sophisticated collaborative workspace that allows humans to work effectively with AI agents. The challenge is in the user experience and system architecture - creating a seamless interface where users can review AI proposals, revert changes, and co-edit schedules in real-time.The Work Split:

• 50% Frontend (Web): Architecting extensive, complex UI for calendar management and AI interaction.
• 30% Backend: Developing robust Node.js/TypeScript services to handle game logic and data.
• 20% LLM Integration: Wiring up the "Co-pilot" features (connecting to LLM APIs, handling prompts/responses) to drive the user experience.

• Lead the UI Solution: Own the frontend architecture of the AI Calendar. You are responsible for designing a "thick client" application that handles complex state, data visualization, and user interactions.
• Build "Co-Pilot" Workflows: Develop the specific UI patterns that make human-AI collaboration possible:
• Review & Revert: Build interfaces that allow users to easily audit AI actions, see what changed, and "rewind" if necessary.
• Co-Editing: Create real-time editing flows where users and AI agents can modify the same schedule simultaneously without conflicts.
• Solid Backend Foundations: Build the Node.js services and APIs needed to support this rich frontend application and manage the data flow between the user and the AI agents.
• Drive Innovation: Take ownership of the feature set. We need someone with Autonomy (Independent/״Rosh Gadol״) who can look at a high-level goal ("make it easier to manage events with AI") and deliver a complete, polished technical solution.

• 5+ years of experience in Fullstack development.
• Expert Frontend Engineering (React): You live and breathe complex UI. You are comfortable managing heavy client-side state, optimizing rendering performance, and building intuitive tools for power users.
• Strong Backend Skills (Node.js/TypeScript): Solid experience building scalable APIs, working with databases, and designing server-side architecture.
• Practical AI Integration: You don't need to be a data scientist, but you should be comfortable integrating LLM APIs (like OpenAI) into a product workflow and handling the unique challenges of non-deterministic AI responses.
• True Independence: You are a self-starter who thrives in fast-paced environments. You solve problems end-to-end without needing constant direction.
• Product-Minded: You care about the end user. You understand that AI is only as good as the interface that allows people to use it.

Bonus Points

• Experience with LangChain or similar libraries.
• Background in Gaming or Internal Tools (LiveOps, CMS, Dashboards).
• Experience building collaborative/real-time editing applications (like Google Docs or similar tools).