Founding Backend Engineer (US) at Robyn AI

At Robyn AI, we’re on a mission to build a more emotionally connected world. We believe in creating products that transform the way people connect and engage. We are backed by elite investors, including M13, Lars Rasmussen (cofounder of Google Maps), Bill Tai (seed investor in Zoom and Canva), and Christian Szegedy (cofounder of X.ai), with $5.5M raised to date.

Robyn is not just an AI app — she’s your emotionally intelligent companion. A trusted mirror. A guide. A new kind of OS for your emotional life.

We're building the world’s first emotional intelligence layer for AI.

As a Founding Backend Engineer, you’ll be building the backend infrastructure that powers all of it:

• Conversations, memory, and real-time personalization

• Voice + chat interface

• Scalable infra for emotional intelligence

• Secure and fast APIs for our iOS app

• A robust ML inference and fine-tuning pipeline

You’ll be the technical backbone of Robyn — designing and shipping fast, scalable, emotionally aware systems while collaborating closely with iOS, product, and AI teams.

1. Backend & Infra Architecture

• Refactor our current C# / .NET Core backend into Python (FastAPI) with modular architecture for scale.

• Build robust REST and GraphQL APIs consumed by iOS; optimize for latency, resilience, and observability.

• Deploy and orchestrate microservices on AWS (EKS) using Docker, Kubernetes, and Terraform.

• Own CI/CD, monitoring, logging, and incident response — full backend autonomy.

2. AI & ML Systems Integration

• Manage vector databases (e.g. Redis Vector, Pinecone) for RAG, memory, and personalization.

• Build and maintain pipelines with LangChain, integrating LLMs (GPT-4o, Claude, Llama 3, etc.).

• Wrap inference APIs (OpenAI, ElevenLabs) with fallbacks, caching, and routing logic.

• Power our emotion and sentiment engine with classifiers and prompt orchestration.

3. Infra, DevOps & Data Engineering

• Own our full AWS stack: EC2, Lambda, S3, RDS, CloudFront, IAM, Route 53.

• Build infra-as-code with Terraform and pipelines via GitHub Actions.

• Optimize performance (Postgres indexing, Redis caching, async pub/sub).

• Stand up observability tooling (Datadog, CloudWatch) and prep for SOC-2 readiness.

4. Emotional Intelligence & Personalization

• Design emotion-aware systems that adapt in real-time to user states.

• Build evolving memory engines with user embeddings and experience graphs.

• Collaborate with product and AI to tune emotional responses, insights, and journaling APIs.

Backend: Python (FastAPI), C# / .NET Core (legacy), PostgreSQL, Redis, GraphQL, REST, WebSockets

Infra: AWS, Terraform, Docker, Kubernetes (EKS), GitHub Actions

Monitoring: Datadog, CloudWatch, Sentry

AI/ML: GPT-4o, Claude, LangChain, HuggingFace, Redis Vector, Pinecone, Whisper, ElevenLabs

• 3+ years of experience in backend or full-stack development

• You’ve shipped entire production backends at high-growth early-stage startups — you know how to move fast and still write code you don’t hate six months later.

• You can work in .NET short-term but prefer Python and modern infra long-term — and you’ve migrated legacy systems before.

• You’ve integrated or scaled LLM-based products — bonus if you’ve done it with emotion, memory, or personalization layers.

• You care about systems thinking, fast response times, clean abstractions, and building infra that won’t fall over under load.

• You’ve done the zero-to-one and can hold both the product in your head and the infra in your hands.

• You're allergic to bloated teams — you’d rather build it right yourself than manage a swarm of mid devs doing it wrong.

• Build the most emotionally intelligent AI product on Earth — at a moment of hypergrowth.

• Work directly with a visionary founder (Harvard-trained surgeon turned CEO).

• Backed by elite investors (Google Maps co-founder, x.ai founder, and more).

• Early team = massive ownership, creative control, and impact.

• Remote-first, async-friendly culture with deep focus and emotional clarity.