Senior Data / AI Infrastructure Engineer

HRvizer is currently supporting a fast-growing AI startup in Berlin in hiring a Senior Engineer to join their core technical team.The company operates in the AI automation space, building production-grade LLM-based systems that help reduce manual, document-heavy workflows in complex, knowledge-intensive environments.They are well-funded, already live with paying customers, and currently scaling their engineering organization.The RoleWe are looking for a Senior Engineer with strong backend and data infrastructure experience to build the foundation for evaluation, observability, and performance optimization of LLM-powered systems.This role sits at the intersection of:Backend engineering Data engineering AI/LLM infrastructure Observability & reliability systems You will work directly on production systems that monitor, evaluate, and improve AI agents at scale.What you will do:Build evaluation frameworks for LLM agents (offline + online testing, datasets, human feedback loops) Design automated quality gates for changes in models, prompts, and agent logic Analyse large-scale production traces to identify failures, regressions, latency, and cost issues Work with analytical databases (BigQuery, ClickHouse or similar) Build data replay, retention, and debugging systems for production behaviour Develop observability tooling (logging, tracing, dashboards, monitoring) Contribute to backend and agent infrastructure where needed RequirementsStrong experience in Python and/or backend engineering Advanced SQL skills and experience with large datasets Experience working in cloud environments (GCP preferred) Experience building data pipelines, ETL/ELT, or event-driven systems Strong understanding of system design, reliability, and observability Ability to work in complex systems and ambiguous environments Strong engineering judgment and architectural thinking Nice to haveExperience with LLMs, agentic systems, or AI infrastructure Experience working with distributed system traces Experience building internal platforms or developer tools Familiarity with workflow orchestration tools (e.g. Temporal) Background in audit, finance, or compliance environments Experience in early-stage startups or scale-ups What’s offeredHigh-impact role in a fast-scaling AI company Strong ownership from day one Competitive salary + equity Learning & development budget Flexible work culture + team events