Senior AI Engineer

Billennium; Poland; Hybrid; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Udemy for Business

Private medical care

Multisport card

Language lessons

Remote/hybrid options

Career growth

Global collaboration

Welcome pack

Job summary

Billennium in Poland is seeking an AI Engineer to design and develop Generative AI and LLM-powered systems. You will build scalable backend services, data pipelines for RAG workflows, and collaborate with data scientists, product owners, and software engineers to deliver production-ready AI applications.

This multidisciplinary role covers backend development, AI engineering, and data engineering across the full AI lifecycle—from data processing and model integration to deployment and

Qualifications

• Experience with Python and SQL in production systems.
• Hands-on with FastAPI/Flask/Django and REST APIs.
• Experience building ETL/ELT pipelines and processing documents.
• Familiarity with cloud platforms (AWS/Azure/GCP) and Docker/Kubernetes.
• Knowledge of LLMs, RAG, embeddings, and prompt engineering.
• Strong communication and collaborative mindset.

Responsibilities

• Design, develop, and maintain scalable backend applications using Python.
• Build AI-powered solutions with LLMs, RAG, and LLM APIs.
• Develop ETL/ELT pipelines for document processing.
• Prepare data for AI applications, including embeddings and vector stores.
• Deploy and operate cloud-native solutions using Docker, Kubernetes, and CI/CD.
• Collaborate with Data Scientists, Product Owners, and engineers to deliver production-grade AI solutions.

Skills

Python

SQL

REST APIs

Analytical thinking

Communication

Team collaboration

Tools

FastAPI

Flask

Django

Pandas

Jupyter Notebook

VS Code

Docker

Kubernetes

Terraform

OpenAI API

Azure OpenAI

Vector stores

Embeddings

Prompt engineering

Job description

Billennium is a global technology company with over 20 years of experience, committed to innovation and empowering businesses. As an employer, we offer a supportive, growth-focused environment where collaboration and creativity thrive. Join us to shape the future of technology together!

Role Purpose

We are looking for an AI Engineer to design and develop solutions powered by Generative AI and Large Language Models (LLMs). In this role, you will build scalable backend services and develop data pipelines that support Retrieval-Augmented Generation (RAG) systems. You will work closely with Data Scientists, Product Owners, and Software Engineers to deliver intelligent, production-ready AI applications.

This is a multidisciplinary role that combines Backend Development, AI Engineering, and Data Engineering, offering the opportunity to work across the full AI application lifecycle—from data processing and model integration to deployment and optimization.

Key Responsibilities

• Design, develop, and maintain scalable backend applications using Python (FastAPI, Flask, Django).
• Build AI-powered solutions leveraging LLMs, RAG, prompt engineering, and LLM APIs (OpenAI, Azure OpenAI, etc.).
• Develop and maintain ETL/ELT pipelines for document processing and data ingestion.
• Prepare data for AI applications, including chunking, embeddings, vector stores, and semantic search.
• Deploy and operate cloud-native solutions using Docker, Kubernetes, and CI/CD pipelines.
• Collaborate with Data Scientists, Product Owners, and engineering teams to deliver production-ready AI solutions.

Required Skills

• Strong proficiency in Python and SQL.
• Experience with FastAPI, Flask, or Django.
• Hands-on experience with Pandas, Jupyter Notebook, and VS Code.
• Experience building ETL/ELT pipelines and processing structured and unstructured documents.
• Solid understanding of REST APIs and backend architecture.
• Experience with cloud platforms (AWS, Azure, GCP, or similar), Docker, and basic Kubernetes.
• Familiarity with CI/CD and Infrastructure as Code (Terraform, Bicep, ARM, or similar).9
• Hands-on experience with LLM APIs, RAG, embeddings, vector databases, and prompt engineering.
• Strong analytical skills, attention to detail, and the ability to work with complex, evolving data sources.
• Excellent communication skills and a collaborative, problem-solving mindset.

Nice to Have

• Experience with LangGraph or similar AI orchestration frameworks.
• Experience with Snowflake, MongoDB Atlas, or other data warehouses.
• Knowledge of OCR, semantic search, and reranking techniques.
• Experience with monitoring tools such as Prometheus, Grafana, or Application Insights.

Perks and benefits:

• Comprehensive benefits - enjoy Udemy for Business, private medical care, Multisport card, veterinary package, language lessons, and shopping vouchers.
• Flexibility - adaptable working hours and remote/hybrid work options to suit your lifestyle & location.
• Career growth - access opportunities for professional development and learning, including perks related to our official partnerships with global IT giants: Microsoft, AWS, Snowflake, Salesforce & more.
• Global collaboration - work with a diverse, international team.
• Innovative environment - be part of a forward-thinking and growth-oriented workplace.
• Engaging community – Work with passionate professionals and participate in team-building events, hackathons, and CSR initiatives to make an impact beyond work.
• Team-building events including our company tradition (annual company event in Mazury).
• A pleasant surprise to start your journey with us in the form of a welcome pack.

Recruitment process:

• HR call
• Technical Interview
• Interview with the dedicated Client