Senior AI Researcher: LLM post-training for hallucination reduction (f/m/d)

<p style="min-height:1.5em"><strong>Who we are</strong></p><p style="min-height:1.5em">Aleph Alpha’s mission is to deliver sovereign, human-centric AI to governmental institutions and large enterprises. To that end, we deliver category-defining AI innovation that enables open, accessible, and trustworthy deployment of GenAI in industrial applications. Our organization develops foundational models and next-generation methods that make it easy and affordable for Aleph Alpha’s customers to increase productivity in development, engineering, logistics, and manufacturing processes. <br /></p><h2><strong>About the role</strong></h2><p style="min-height:1.5em">We are looking for a <strong>(Senior) AI Researcher</strong> to join our hallucination reduction capability team to push the boundaries in LLM post-training (SFT and RL).</p><p style="min-height:1.5em">We're one of the few places in Europe training foundation models from scratch. You will be part of a team of (senior) researchers and PhD interns doing cutting-edge research across pre-, mid- and post-training, grounding and specialized models with hundreds of GPUs at our disposal.<br /></p><h2><strong>What will you do</strong></h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em"><strong>Core Research &amp; Development:</strong> Design, execute, and scale post-training methodologies (SFT, RL) specifically aimed at eliminating model hallucinations and making them grounded in evidence.</p></li><li><p style="min-height:1.5em"><strong>Uncertainty &amp; Reliability:</strong> Research and implement techniques in uncertainty estimation, calibration, self-consistency, and self-correction mechanisms to enable models to identify and signal when they “don't know”.</p></li><li><p style="min-height:1.5em"><strong>Post-Training Pipelines:</strong> Build and optimize high-throughput, distributed fine-tuning and training pipelines across multi-node GPU clusters.</p></li><li><p style="min-height:1.5em"><strong>Evaluation &amp; Benchmarking:</strong> Design and implement rigorous evaluation methods to benchmark hallucination rates, truthfulness, and reasoning accuracy.</p></li><li><p style="min-height:1.5em"><strong>Technical Ownership:</strong> Drive research projects independently from initial hypothesis to scalable production implementation and technical reports.</p></li></ul><h2><strong>Qualifications</strong></h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Hands-on experience fine-tuning or post-training LLMs using modern distributed training frameworks.</p></li><li><p style="min-height:1.5em">Track record of research or implementation in at least one of the following domains:</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Hallucination mitigation / truthfulness alignment / grounding in RAG</p></li><li><p style="min-height:1.5em">Uncertainty estimation, or out-of-distribution detection</p></li><li><p style="min-height:1.5em">Retrieval-Augmented Generation evaluation / alignment, refusal behavior calibration, or claim verification</p></li></ul></li><li><p style="min-height:1.5em">Strong programming skills (Python &amp; PyTorch).</p><p style="min-height:1.5em"></p></li></ul><h2>Compensation and Benefits</h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Become part of an AI revolution!</p></li><li><p style="min-height:1.5em">30 days of paid vacation</p></li><li><p style="min-height:1.5em">Access to a variety of fitness &amp; wellness offerings via <a target="_blank" rel="noopener noreferrer" class="theme markdown__link" href="https://wellhub.com/de-de/">Wellhub</a></p></li><li><p style="min-height:1.5em">Mental health support through <a target="_blank" rel="noopener noreferrer nofollow" href="http://nilo.health">nilo.health</a></p></li><li><p style="min-height:1.5em">Substantially subsidized company pension plan for your future security</p></li><li><p style="min-height:1.5em">Subsidized Germany-wide transportation ticket</p></li><li><p style="min-height:1.5em">Budget for additional technical equipment</p></li><li><p style="min-height:1.5em">Flexible working hours for better work-life balance and hybrid working model</p></li><li><p style="min-height:1.5em"><a target="_blank" rel="noopener noreferrer" class="theme markdown__link" href="https://www.jobrad.org/">JobRad®</a> Bike Lease</p></li></ul><p>Find <a href="https://www.arbeitnow.com">Jobs in Germany</a> on Arbeitnow</a>