Alephalpha

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

Heidelberg, Germany full-time Mid Salary not listed
full-time Mid level Technology & IT Curated
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About the role

Who we are
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.

About the role
We are looking for a (Senior) AI Researcher to join our hallucination reduction capability team to push the boundaries in LLM post-training (SFT and RL).
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.

What will you do
Core Research & Development: Design, execute, and scale post-training methodologies (SFT, RL) specifically aimed at eliminating model hallucinations and making them grounded in evidence.

Uncertainty & Reliability: 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”.

Post-Training Pipelines: Build and optimize high-throughput, distributed fine-tuning and training pipelines across multi-node GPU clusters.

Evaluation & Benchmarking: Design and implement rigorous evaluation methods to benchmark hallucination rates, truthfulness, and reasoning accuracy.

Technical Ownership: Drive research projects independently from initial hypothesis to scalable production implementation and technical reports.

Qualifications
Hands-on experience fine-tuning or post-training LLMs using modern distributed training frameworks.

Track record of research or implementation in at least one of the following domains:
Hallucination mitigation / truthfulness alignment / grounding in RAG

Uncertainty estimation, or out-of-distribution detection

Retrieval-Augmented Generation evaluation / alignment, refusal behavior calibration, or claim verification

Strong programming skills (Python & PyTorch).

Compensation and Benefits
Become part of an AI revolution!

30 days of paid vacation

Access to a variety of fitness & wellness offerings via Wellhub

Mental health support through nilo.health

Substantially subsidized company pension plan for your future security

Subsidized Germany-wide transportation ticket

Budget for additional technical equipment

Flexible working hours for better work-life balance and hybrid working model

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Interview prep

Walk in with sharper answers.

Use this as a quick practice sheet before you speak with the employer.

Mid
Technology & IT Operations Python Senior Researcher Llm Mid level

Likely questions

  1. Tell us about work you have done that is close to the Senior AI Researcher: LLM post-training for hallucination reduction (f/m/d) role.
  2. How would you approach your first 30 days at Alephalpha?
  3. Which of Operations, Python and Senior have you used recently, and what did it help you achieve?
  4. Describe a time you solved a problem without waiting to be told exactly what to do.
  5. How do you handle busy days, changing priorities, or pressure at work?

Prepare before the call

  • A recent example that proves your experience with Operations, Python and Senior.
  • One short story with a problem, your action, and the result.
  • Two examples that show the strengths listed on your CV.
  • A clear reason why this role and company interest you.
  • Your availability, preferred work style, and salary expectations.

Ask them

  • What would success look like in the first 90 days?
  • What are the main problems this hire should help solve?
  • How does the team give feedback and measure good work?
  • What does a normal working week look like for this role?
Practice line

I am interested in the Senior AI Researcher: LLM post-training for hallucination reduction (f/m/d) role because I can bring practical experience in Operations, Python and Senior, learn the team quickly, and contribute to the outcomes Alephalpha needs from this hire.

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