O pozici
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/
About the role
At Ruby Labs, we are building a Direct-to-Consumer product in the AI category. We’re looking for a Junior AI Engineer (Node.js / Next.js / TypeScript) to join our AI engineering team and contribute to production-ready LLM experiences.
You’ll work alongside senior engineers in a modern stack, learning to make data-driven decisions around model performance, reliability, and cost. You’ll contribute to prompt systems, structured outputs, and LLM workflows while building familiarity with observability and evaluation tooling like Langfuse and AI gateways like OpenRouter.
This is a hands-on role where you will grow quickly by shipping real AI features to production under the guidance of experienced teammates.
Co budeš dělat
- Implement AI-powered product features and workflows based on specifications from senior engineers.
- Write, iterate on, and manage production prompt templates following established patterns for dynamic prompting and context injection.
- Participate in prompt experimentation workflows by drafting variants, running A/B tests across models via OpenRouter, and documenting results.
- Integrate structured output schemas (JSON mode, function calling, Zod/JSON schemas) to ensure AI responses are predictable and application-ready.
- Build and maintain output enforcement mechanisms such as validators and repair loops under senior guidance.
- Help implement tool calling and function calling integrations so AI features can fetch data or trigger actions, following patterns established by senior engineers.
- Contribute to evaluation pipelines and help assess prompt and model quality using Langfuse.
- Write clean, maintainable TypeScript code within the Next.js and Node.js stack.
- Participate in code reviews and incorporate feedback.
- Document technical decisions and system behaviour to support knowledge sharing.
- Collaborate with product, growth, data, and billing teams to deliver features on time.
Koho hledáme
- 0–2 years of software engineering experience — recent graduates, bootcamp graduates, and early-career engineers are welcome.
- Working knowledge of Node.js, Next.js, and TypeScript.
- Basic understanding of how LLMs work and hands-on experience using LLM APIs (OpenAI, Anthropic, or similar).
- Experience writing prompts that go beyond simple instructions, such as using variables, templates, or conditional logic.
- Familiarity with structured outputs (JSON mode, function calling, or schema validation).
- Understanding of basic web application architecture, RESTful APIs, and backend fundamentals, including request validation, error handling, and logging.
- Curiosity and willingness to learn quickly in a fast-moving AI product environment.
- Strong communication skills and a collaborative mindset.
Benefity
- Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
- Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
- Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and
- ortunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1nkrN76JlZkbKj9WSOhlT1_mni_CZeDkHdwfIjPXVwvk/preview?tab=t.0#heading=h.ndsdl4wapxtt
