Senior AI Researcher LLM Post Training for Hallucination Reduction

German enterprise AI company building and deploying specialized large language models for sovereign, mission-critical use cases.

Series A0 current maintainers0 active leadsTeam intelligence

Maintainer signals as of 9/25/2026

Heidelberg, Germany

Funding history

About Aleph Alpha GmbH

Aleph Alpha designs, builds, and deploys specialized large language models with enterprises and public institutions, emphasizing European infrastructure, data sovereignty, compliance, explainability, and domain-specific performance.

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Skills

Candidate Availability

Required and preferred rules are kept separate and reflect the wording in the original posting.

About the Role

You will research, develop, and scale LLM post-training methods, including supervised fine-tuning and reinforcement learning, to reduce hallucinations and ground model outputs in evidence. You will implement uncertainty, calibration, self-consistency, and self-correction techniques; build distributed GPU training pipelines; create evaluation benchmarks; and independently take research projects from hypotheses through production implementation and technical reports.

Requirements

  • Hands-on experience fine-tuning or post-training LLMs using distributed training frameworks
  • Research or implementation experience in hallucination mitigation, truthfulness alignment, RAG grounding, uncertainty estimation, out-of-distribution detection, RAG evaluation, refusal behavior calibration, or claim verification
  • Strong Python and PyTorch programming skills

Responsibilities

  • Design, execute, and scale LLM post-training methodologies to reduce hallucinations and improve evidence grounding
  • Research and implement uncertainty estimation, calibration, self-consistency, and self-correction mechanisms
  • Build and optimize distributed fine-tuning and training pipelines across multi-node GPU clusters
  • Design and implement evaluation methods for hallucination rates, truthfulness, and reasoning accuracy
  • Drive research projects from hypothesis through scalable production implementation and technical reporting

Benefits

  • 30 days of paid vacation
  • Fitness and wellness offerings through Wellhub
  • Mental health support through nilo.health
  • Subsidized company pension plan
  • Subsidized Germany-wide transportation ticket
  • Budget for additional technical equipment
  • Flexible working hours
  • Hybrid working model
  • JobRad bike lease