### **About Us** We are a **stealth-mode startup** building a new AI platform. Our mission is to make advanced language models deployable, customizable, and secure across diverse environments. ### **Role** We are seeking a **Backend Engineer (https://jobeax.com/link/k0MXLUXcpjpZfTVN to extend our platform using our existing codebase. You'll build the **proxy backend** that interacts with our custom inference runtime and extend dashboards. This role requires strong backend engineering skills, the ability to integrate existing systems, and comfort working closely with C++/CUDA engineers building low-level runtime features.

## **Responsibilities**
### **Proxy Backend for Inference Runtime**

Build and maintain a **Node.js-based proxy backend**that:
Accepts inference requests from the frontend.
Schedules and serializes prompts.
Manages **QKV cache load/unload**.
Provides APIs to **manage LoRA adapters**.
Integrate with authentication, RBAC, and logging already provided by the existing stack.
Expose metrics and logs for monitoring inference usage and performance.

#### **Dashboards**

Extend the existing Dashboard with Dataset upload, training job view, model management, inference usage, request history, and adapter selection.
Reuse **auth, billing, and user management code** (Auth0, Stripe).
Add necessary backend endpoints to support new UI flows.

#### **Core Stack & Infrastructure**

Develop using **NestJS** as the main backend framework.
Work with **PostgreSQL, Redis, and HashiCorp Vault** for persistence, caching, and secrets.
Use **Socket.IO** for real-time updates (job status, inference progress).
Ensure secure integration with Stripe (billing) and Auth0 (identity).
Collaborate with DevOps on deployment pipelines (Proxmox, Docker, CI/CD).

### **Requirements**

Strong experience with **Node.js** and **NestJS** framework.
Proficiency in **PostgreSQL** and **Redis** for persistence and caching.
Hands-on experience with **Socket.IO** or other WebSocket libraries.
Experience with **secure configuration and secrets management** (HashiCorp Vault preferred).
Comfortable working with **microservices** and integrating with existing codebases.
Strong debugging and systems thinking — able to reason about scheduling, state management, and concurrency.
Familiarity with LangChain for building AI-powered features and workflows.

### **Nice to Have**

Experience integrating with **AI runtimes** (gRPC/REST backends for inference).
Experience with RAG and MCP.
Experience with **authentication/authorization frameworks** (Auth0, JWT, RBAC).
Familiarity with **Stripe API** or similar billing systems.
Contributions to backend open-source projects.
Experience with WebRTC.

### **Why Join**

Extend a proven SaaS foundation into a **new AI runtime platform**.
Competitive compensation, equity potential.

Backend Engineer (Node.js/NestJS) —Lisbon, Portugal

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