TWINii

About the Role

We're building AI-powered products and we need someone who can work across the full stack without needing a handoff at every layer. This role spans backend services, AI orchestration, real-time voice systems and frontend interfaces. You'll own features from design to deployment and be expected to debug issues that cut across all of them.

If your experience is limited to a single layer of the stack, or your AI exposure hasn't gone beyond side projects, this role isn't the right fit.

What You'll Do

• Design and build backend services and APIs using Node.js and Python
• Build and operate AI workflows using LangChain and LangGraph for orchestration, chaining and agent logic
• Use LangSmith for tracing, evaluation and debugging of AI pipelines in production
• Integrate real-time voice capabilities using LiveKit and related voice AI infrastructure
• Build frontend interfaces using React and Next.js that are fast, reliable and handle streaming AI responses cleanly
• Own features end to end from initial design through deployment, monitoring and iteration
• Handle async workflows, background jobs and real-world failure scenarios
• Set up logging, tracing and alerting so production issues surface before users report them
• Debug problems that span frontend, backend, AI pipelines and infrastructure simultaneously
• Work with product to turn vague requirements into well-scoped, shipped features
• Review code and maintain technical standards across the team

What You'll Need

• 5+ years of professional software engineering experience in production environments
• Strong hands-on experience with Node.js and Python at production scale
• Demonstrated experience building AI workflows using LangChain, LangGraph or comparable frameworks
• Working knowledge of LangSmith or equivalent tooling for AI observability and evaluation
• Experience building and operating backend APIs used by real users
• Solid experience with React and Next.js or equivalent frontend frameworks
• Strong understanding of async programming, streaming (SSE/WebSocket) and frontend state management
• Experience with MongoDB or similar document stores including data modelling trade-offs
• Comfort deploying and operating services on AWS, GCP or equivalent cloud environments
• Ability to debug across frontend, backend and AI layers using logs, traces and metrics

Good to Have

• Hands-on experience with LiveKit or other real-time voice and audio pipeline systems
• Prior work on conversational AI, voice agents or multi-modal AI products
• Experience with RAG pipelines, LLM evaluation or fine-tuning workflows
• Background in a fast-moving startup or high-velocity product environment

What We Expect

• You take ownership of what you build and don't wait for someone else to fix broken things
• You understand trade-offs and can communicate them clearly to non-engineers
• You think in systems, account for failure modes early and design for graceful degradation
• You leave code and documentation in better shape than you found it

What You'll Get

• End-to-end ownership of features that ship to real users
• Direct influence over technical and architectural decisions
• Work on systems that are used daily by real users
• A small team where your contributions have visible product impact