Senior Full Stack AI Engineer

Company: TWINii.ai

Backend, AI & Frontend / Fully Remote
Full-time Contractor
About TWINii
TWINii is an expert-powered AI companion platform. We help the world's most trusted experts turn their voice, perspective, and body of work into an interactive AI twin their audience can talk to, any time. Personal, practical, scalable. A relationship, not a feed. A companion, not another app.
We are building the next layer of expert-audience connection. Not a feed to scroll, but a conversation you can apply. Our mission: give experts full consent and full ownership of their AI twin, backed by an architecture designed for depth, trust, and real intent.
Where We Are
Pre-launch. Funded. Engineering team of 6, based primarily in India. The core product, voice and chat interaction with expert twins, is live internally. We are hiring the person who will own our AI and full-stack systems end to end as we scale to public launch and beyond.
The Role
We are 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 will 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 has not gone beyond side projects, this role is not the right fit.
Core Responsibilities
Backend and APIs. Design and build backend services and APIs using Node.js and Python, used by real users at production scale.
AI Orchestration. Build and operate AI workflows using LangChain and LangGraph for orchestration, chaining, and agent logic.
AI Observability. Use LangSmith for tracing, evaluation, and debugging of AI pipelines in production.
Real-Time Voice. Integrate real-time voice capabilities using LiveKit and related voice AI infrastructure.
Frontend. Build frontend interfaces using React and Next.js that are fast, reliable, and handle streaming AI responses cleanly.
End-to-End Ownership. Own features end to end, from initial design through deployment, monitoring, and iteration.
Resilience. Handle async workflows, background jobs, and real-world failure scenarios. Set up logging, tracing, and alerting so production issues surface before users report them.
Cross-Layer Debugging. Debug problems that span frontend, backend, AI pipelines, and infrastructure simultaneously.
Product Partnership. Work with product to turn vague requirements into well-scoped, shipped features.
Standards. Review code and maintain technical standards across the team.
Required Technical Skills
* 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 Senior Means at TWINii
This section matters to us. If it resonates, you are probably the right person.
You take ownership of what you build and do not wait for someone else to fix broken things. If something breaks in production, you are already investigating before anyone asks.
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 have shipped and maintained a product over time, not just built features and moved on.
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 people. A small team where your contributions have visible product impact.
How to Apply
Email engineering@twinii.ai with:
A link to a repository, portfolio, or production AI products you have shipped.
And Answers To These Three Questions
* Tell us about an AI workflow you built and shipped to production using LangChain or LangGraph: what it did, how you orchestrated it, and how many users it served.
* Tell us about an architectural decision that shaped a project: what you chose, why, and what you would do differently now.
* Tell us about a bug you debugged that spanned frontend, backend, and the AI layer at the same time. How did you isolate it, and what was the result?
We value engineers who own outcomes, understand the full stack under the hood, and ship AI that real people use.
Applications must be sent to engineering@twinii.ai. Applications sent to any other TWINii email address will not be considered.
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Last updated: June 2026

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