Loading...
Loading...
Ruby Labs is seeking a Senior AI Engineer to manage and enhance their AI systems in production. This role involves end-to-end delivery of AI features, ensuring production stability, and conducting data-driven experiments. You will work with a modern tech stack including Next.js, TypeScript, and Node.js, and focus on building agentic AI systems and integrating LLM providers. The position requires strong ownership, backend/full-stack experience, and specific expertise in AI/LLM systems.
Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about-us/
At Ruby Labs we are looking for a Senior AI Engineer to own and drive the quality, reliability, and evolution of our AI systems in production.
This is a high-ownership role. You will be responsible for end-to-end delivery of major AI features, production stability of AI systems, and data-driven experimentation using tools like Langfuse, Mixpanel and OpenRouter. You’ll work in a modern stack built on Next.js, TypeScript, Node.js, and Redis, collaborating closely with product, growth, data, and billing teams. Increasingly, this includes building agentic, tool-using AI systems — defining clean tool contracts (including MCP-based tools) and orchestrating how AI interacts with internal services and business systems.
Our engineering organization uses a squad-based structure. You will operate within an AI engineering squad, contributing as a senior technical voice and driving engineering quality within your area of the product.
AI Systems Ownership & Feature Delivery
• Take complete ownership and deliver major AI engineering features within agreed timelines
• Own AI output quality, structure, and predictability across all user-facing AI interactions
• Design, implement, and maintain output-type–based AI systems, including segmentation, routing, and enforcement
• Ensure consistent output structure and formatting across different LLMs for the same request type
• Integrate and orchestrate multiple LLM providers via OpenRouter, managing model selection, fallback strategies, and cost optimisations
• Design and orchestrate tool-using / agentic AI workflows — defining clean tool contracts (including MCP-based tools), function-calling interfaces, and reliable AI-to-system integrations
• Build and maintain complex, multi-step LLM workflows — including with orchestration frameworks such as LangChain or LlamaIndex — for advanced reasoning, context reuse, and retrieval
Prompt Engineering & Experimentation
• Design and manage production prompt systems with dynamic prompting, context injection, and conditional logic
• Own the deployment and release of LLM experiments, prompt management, and Langfuse-based evaluation pipelines
• Run A/B tests across models, analyse results, and present data-driven impact assessments of AI features and experiments
• Monitor AI system metrics, quality signals, latency, and release health using Langfuse and other observability tools
• Deep-debug complex LLM chains using Langfuse traces — identifying bottlenecks and optimising for cost, latency, and context-window usage — and build output-scoring to root-cause hallucinations and logic errors
Code Quality & Production Reliability
• Write clean, scalable, and maintainable TypeScript code across the Next.js / Node.js stack
• Build reliable backend logic for AI systems, with strong error handling, request validation, fallback flows, and predictable behavior in production — including reliable tool execution and AI-to-service integrations
• Ensure high code quality through testing, code reviews, and clear engineering standards
• Monitor, troubleshoot, and improve production performance, reliability, and system health
• Drive maintainability and technical quality through solid architecture, refactoring, and disciplined release practices
Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.
Discover the perks of being part of our vibrant team! We offer:
Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!
After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:
At Ruby Labs, we move fast, aim high, and expect the same from our team. We’re not here to play small—we’re here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.
This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.
Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more—more responsibility, more growth, and more success.
#LI-Remote
