Senior AI Engineer (m/f/n)

About the Position

We are looking for a Senior AI Engineer (m/f/n) to join our team at InPost Group. This role is pivotal in leading the development of our conversational AI shopping assistant, Von Halsky, and influencing our future platform build.

Responsibilities

• The LLM-judge pipeline: Our release-gating judge over real and golden conversations, calibrated well enough that people act on its verdicts instead of arguing about it.
• Eval datasets and the golden set: Real coverage across intents and categories, including the Polish-language coverage generic benchmarks do not give us.
• Root-cause analysis on real conversations: Making our conversation-mining stack diagnostic rather than descriptive, on a stable issue taxonomy.
• The "sus" detector: Abusive, adversarial and anomalous sessions, next to our guardrails and red-team work.
• Evals-driven development: The eval comes before the feature, and writing it is as cheap as writing the code.
• The interface to product and business: Vague asks in, measurable quality definitions out, and results stakeholders can act on.

Requirements

• 5+ years building and running production software, with 2+ years on LLM-based systems that real users hit.
• Strong engineering fundamentals, plus the habits that go with production ownership: testing, CI/CD, containers, observability, and working in cloud. We work primarily in Python.
• Demonstrable experience evaluating generative systems, not only building them: LLM-as-judge, human-label calibration, inter-annotator agreement, regression suites, offline-versus-online divergence. You should have opinions about what makes an eval worthless.
• AI engineering fundamentals: Prompt and context engineering as a discipline (context-window budgeting, structured outputs, failure-mode taxonomies); agentic primitives in production (tool use, multi-turn state, MCP, agent-to-agent integration patterns); and eval and LLM-observability tooling (LangFuse, Braintrust, Weave or equivalent, including things you built yourself).
• Comfort with data at scale: SQL, working with a lake or warehouse, and building a metric someone else can reproduce.
• Fluency with AI-assisted development tooling (Claude Code, Cursor, Copilot). We use it daily and expect it.
• Ability to make a technical argument to a non-technical audience and be understood.
• English B2 and Polish. Our users converse in Polish and you will read their conversations; judging quality you cannot read is not possible.

Nice to Have

• Harness and loop engineering: Building the scaffolding around models rather than only calling them: agent loops, retries and fallbacks, tool-call orchestration, deterministic replay, and the plumbing that makes a non-deterministic system testable.
• Auto-improving systems: Closing the loop from production signal back into the product: mining failures into cases, using eval results to drive prompt, retrieval and routing changes, and automating the parts of that cycle that people do by hand today.
• Adversarial robustness, jailbreak testing, red-teaming, or abuse and fraud detection.
• E-commerce, search or recommendation domain experience.

We Offer

• A product that has already been released to millions of users, with a real business case, not a lab pilot.
• Direct access to frontier models at committed capacity across multiple providers, plus an open-source track we run ourselves.
• A quality mandate with executive attention.
• Ownership of a platform that is greenfield in practice inside a company with production traffic, which is the rarest combination in this market.
• Hybrid working from Warsaw or Kraków, in a team growing fast enough that early hires shape how it works.
• Fulfilling careers with a range of benefits for people and investing in providing training opportunities for their development.
• You will feel a part of the InPost community that makes an impact on sustainability, convenient deliveries, and the circular economy every day.
• Excellent working environment and flexible hours
• We offer B2B type of contract

About the Company

InPost Group is an innovative European out of home deliveries company, revolutionizing the way parcels are delivered to customers. With operations across several countries, our network of intelligent lockers provides customers with a fast, convenient, and secure delivery option. InPost Group is a publicly traded company, with a market capitalization of about $5 billion as of March 2023. With over 10,000 people worldwide, InPost Group is one of the largest out of home delivery providers in Europe, committed to providing sustainable and efficient delivery solutions to meet the evolving needs of customers in today's rapidly changing landscape.

We are a team that builds the best FMCG e-commerce in Poland. We already have over 300,000 products in our offer, we work with over 300 sellers, and our mobile application has already been downloaded by almost 1.5 million users in Poland. Due to the fact that our product consists of many elements that must work together efficiently and be managed effectively, we are looking for experienced consumer-focused (Web / Mobile App products) engineering leaders to join us in that journey - heavily influence our future platform build, improve processes and help us deliver best customer experience in the market across all types of devices.

Job Location

• City: Warsaw, Poland
• City: Kraków, Poland