Senior AI Engineer — Remote, Production-Grade LLM Systems

Ruby Labs; United States; Remote; USD 120,000 - 180,000; Part time

Benefits offered by this job

Remote Work Environment

Unlimited PTO

Paid National Holidays

Company-provided MacBook

Flexible Independent Contractor

Job summary

Ruby Labs is seeking an AI Engineer (Strong Middle / Senior) to own the end-to-end delivery and reliability of AI features in production. You will orchestrate multi-LLM providers through an AI gateway, design tool contracts, and build robust LLM pipelines for reasoning, retrieval, and search.

You will ship high-quality backend and frontend features in a TypeScript/Node.js stack on Cloudflare Workers, ensuring output quality and cost-efficient model usage while continually improving prompts and

Qualifications

• 4+ years backend/fullstack software engineering with production-grade TypeScript/Node.js
• 1+ year AI/LLM systems in production with real users
• Daily use of AI-centred development tools
• Deep hands-on with LLM APIs (OpenAI, Anthropic, Google Gemini) in production
• Experience with agentic AI, multi-step orchestration, tool-based workflows or RAG pipelines
• Experience with LLM observability and evaluation tools (Langfuse, LangSmith)
• Experience with AI gateways and model routing (OpenRouter, Cloudflare AI Gateway)
• Strong relational DB (PostgreSQL) and caching (Redis) knowledge
• Exceptional ownership and delivery responsibility

Responsibilities

• Take ownership of major AI features and LLM workflows and deliver them to production
• Own AI output quality, structure and predictability across user-facing AI interactions
• Integrate and orchestrate multiple LLM providers through an AI gateway
• Design tool-using and agentic AI workflows with clean tool contracts
• Build and maintain multi-step LLM workflows and RAG pipelines for reasoning and search
• Design and manage production prompt systems with dynamic prompting and context injection
• Own prompt management and Langfuse-based evaluation pipelines
• Run A/B tests across models and prompts and analyse results
• Deep-debug LLM chains using Langfuse traces for cost, latency and accuracy
• Write clean, scalable TypeScript and ensure reliable AI system behavior
• Monitor AI system metrics and document prompts and architectural decisions

Skills

TypeScript/Node.js

AI/LLM systems

Langfuse

Tool contracts

Prompt engineering

Observability

PostgreSQL

Cloudflare Workers

LLM providers

Prototyping

Tools

OpenSearch

PostgreSQL

Redis

Cloudflare Workers

LangSmith

RAG pipelines

Job description

Ruby Labs is seeking an AI Engineer (Strong Middle / Senior) to own the end-to-end delivery and reliability of AI features in production. You will orchestrate multi-LLM providers through an AI gateway, design tool contracts, and build robust LLM pipelines for reasoning, retrieval, and search.

You will ship high-quality backend and frontend features in a TypeScript/Node.js stack on Cloudflare Workers, ensuring output quality and cost-efficient model usage while continually improving prompts and