AI Engineer

This a Full Remote job, the offer is available from: Africa, Cyprus, Israel, Turkey, Estonia, Latvia, Ukraine, Poland, Kazakhstan, Malta, Slovakia, Czechia, Montenegro, Brazil, Serbia, Georgia (USA) About us 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 RubyLabs, we’re seeking a senior AI Engineer (Node.js / Next.js / TypeScript) to shape our AI infrastructure and drive production-ready LLM experiences.

You’ll work in a modern stack, making data-driven decisions around model performance, reliability, and cost.

You’ll own advanced prompt systems, structured outputs, and complex LLM workflows using LangChain or LlamaIndex.

Observability, debugging, and evaluation are core to the role, leveraging Langfuse and AI gateways like OpenRouter to continuously improve model quality and operational efficiency.

You’ll take full ownership of key AI features from experimentation to live production.

Key Responsibilities • Advanced Prompt Engineering: Designing complex, dynamic prompt templates with conditional logic and efficiently reusing information and context within prompts to maximize generation quality and reasoning.

GPT-4o) and analyzing results based on quantitative metrics. • Data-Driven Decisions: Making deployment decisions for new prompts or models strictly based on quantitative benchmarks and trace data, rather than intuition.

Qualifications • Node.js & Next.js: Deep knowledge of the stack to build reliable services and handle complex LLM-generated data.

Nice to have • Fine-Tuning: Practical experience in fine-tuning models for specific domain tasks or JSON compliance.

Location 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.

Benefits Discover the perks of being part of our vibrant team! We offer:

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/1tzxGX4Uu7Ts_HCLFXESKLnKaaBfVCPf1f9AYZPrkjJM/preview?tab=t.0 Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth! Interview Process 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:

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 This offer from "Ruby Labs" has been enriched by Jobgether.com and got a 83% flex score.