Senior AI Engineer (LLM)

Location: Warsaw/Cracow (hybrid: 1-2 days per week in the office)Contract: B2BSalary: 25.000 - 33.000 PLN net B2BHow this role works:You will start by building the system as part of our team, working in a focused, greenfield setup. After a few months of introduction to the project, you will seamlessly continue working on the same product directly with the client, becoming part of the client’s team responsible for its long-term development and scaling. There is no handover phase and no context switching - you stay with the same codebase, product, and technical challenges, while gaining long-term ownership and impact.What you’ll work on:Designing, implementing, and deploying end-to-end NLP and deep learning systemsBuilding LLM-powered applications that interact with real usersDeveloping and maintaining production Python servicesExposing models and pipelines via REST APIs (FastAPI, Flask)Working on retrieval models and techniques (RAG, embeddings, ranking)Evaluating, monitoring, and continuously improving model and system qualityScaling systems to handle enormous volumes of requestsBiggest challenges in this role:Greenfield project built from scratchHigh-scale, user-facing systems with strict performance and reliability requirementsDesigning systems meant for long-term ownership, not short-term deliveryBalancing model quality, latency, and cost in production LLM systemsWhat you’ll learn:How to build LLM-powered products from scratch and take them to productionProven approaches to running LLMs in production at scaleHow to design, evaluate, and evolve NLP systems used by real usersBest practices for production ML and AI system architectureWhat you’ll get to try and experiment with:End-to-end ownership of LLM-based systemsOptimizing retrieval models, RAG pipelines, and inference workflowsExperimenting with different LLMs, prompting strategies, and system designsSolving performance and reliability challenges under heavy traffic