---
title: 'Senior AI Researcher: LLM post-training for hallucination reduction (f/m/d) at Aleph Alpha'
canonical: 'https://feeny.ai/job/senior-ai-researcher-llm-post-training-for-hallucination-reduction-f-m-d-aleph-zap2g8gcb5g4'
type: 'job'
last_seen: '2026-10-18'
---

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

- **Company:** Aleph Alpha
- **Location:** Heidelberg, Germany
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-10-14
- **Last confirmed live:** 2026-10-18
- **Apply:** https://jobs.ashbyhq.com/alephalpha/fce0b58f-e95a-45bc-9ca5-b47b1c3cbabd

## Job description

## 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](https://wellhub.com/de-de/)
- Mental health support through [nilo.health](http://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
- [JobRad®](https://www.jobrad.org/) Bike Lease

## About Aleph Alpha

## Company Overview
- **One-liner**: Aleph Alpha is a German AI startup that develops sovereign large language models (SLLMs) for enterprises and governments, emphasizing data sovereignty, regulatory compliance, and domain-specific performance.
- **Entity Type**: Private (Series B; acquired by Cohere in a landmark agreement)
- **Headquarters**: Heidelberg, Baden-Württemberg, Germany
- **Founded**: 2019
- **Founders**: Jonas Andrulis, Samuel Weinbach

## Core Business
- **Primary industry/industries**: Artificial Intelligence (Generative AI, Large Language Models), Enterprise Software, Government Technology
- **Target customers**: B2B exclusively — enterprises in industry, public sector, and defense where data sovereignty and domain expertise are critical
- **Mission or purpose statement**: "We empower enterprises and public institutions to transform their most critical knowledge." The company operates under the principles of Trust, Responsibility, and Sovereignty.

## Products & Services
- **Luminous LLM**: A family of large language models designed for enterprise and government use, with a focus on transparency of sources used to generate results. The models are trained on customer-specific domains (legal, administrative, industrial, scientific) and run exclusively on European infrastructure.
- **Sovereign Large Language Models (SLLMs)**: Custom-built, secure language models tailored to a customer's domain and workflows, paired with custom evaluation frameworks to ensure performance before deployment.
- **AI Agent Solutions**: Deployed for tasks like retrieving verifiable insights from sensitive documentation (e.g., reducing search time by 90% at a global chip manufacturer) and AI-powered requirements engineering (e.g., 40% time savings on RFQ processing for an automotive supplier).
- **AI Assistant for Government**: A sovereign AI assistant deployed in a government agency, empowering 80,000 users to streamline administrative processes.

## Market Standing
- **Valuation/Market Cap**: Not publicly disclosed (private company)
- **Key Metric**: Annual Revenue of $100M (as of latest data); Total Funding of $633.6M (across 6 rounds, including a $500M Series B led by Schwarz Group, Bosch Ventures, and others)
- **Notable Investors/Partners**: Cohere (acquirer), Schwarz Group, Bosch Ventures, 468 Capital, LEA Partners, Lakestar, EarlyBird, and 18+ other investors. Key partners include global chip manufacturers, automotive suppliers, and government agencies.
- **Growth Signals**: Headcount of 275 employees (+17% YoY); operates in 9 countries (Germany, Switzerland, Romania, Nigeria, Brazil, France, Peru, Austria, Netherlands); acquired thingsTHINKING (April 2025); landmark agreement with Cohere for operational realignment and partnership.

## Competitive Advantages
- **Data Sovereignty & Compliance**: All models run on European infrastructure and are trained in accordance with EU law, making them uniquely suited for regulated industries (defense, public sector, legal) where data cannot leave the continent.
- **Domain-Specific Customization**: Unlike general-purpose models, Aleph Alpha's SLLMs are trained on a customer's own domain knowledge and workflows, with custom evaluation frameworks that prove performance before deployment.
- **Proven Track Record in Sensitive Environments**: Demonstrated success in government (80,000 users), defense, and industrial settings where precision and reliability are non-negotiable.
- **End-to-End Partnership Model**: The company co-builds solutions with customers from first use case through production deployment, ensuring the technology fits existing processes.

## Strategic Focus
- **Current priorities**: Deepening the partnership with Cohere for operational realignment and scaling; expanding sovereign AI solutions for European enterprises and governments; continuing to build domain-specific SLLMs for legal, administrative, industrial, and scientific sectors.
- **Direction for growth**: Focus on mission-critical, sensitive environments where general-purpose AI fails; expanding across European public sector and defense; leveraging the Cohere partnership for broader reach and resources.

## Why Work Here
- **Culture highlights**: The company emphasizes collaboration, openness, and a deep commitment to responsibility. The team is described as international, with engineers, scientists, and innovators working across four German locations. The mission is centered on "Trust. Responsibility. Sovereignty."
- **Remote/hybrid/office policy**: Based on job postings, roles are primarily on-site in Heidelberg, with some flexibility. The company has locations in Heidelberg, Speyer, and other German cities.
- **Notable perks or engineering culture**: Strong focus on research and engineering (33% of workforce in technical roles, 8% in research). The tech stack includes TensorFlow, Kubernetes, Flask, MLflow, and more. The company has filed 4 patents related to AI model compression and performance. Recent departures of key executives (e.g., Co-CEO Ilhan Scheer, COO Ben Oppl) suggest a period of transition, but the company is actively hiring for senior AI research and engineering roles.
- **Employee ratings**: 3.2/5.0 on employer review platforms (Work-Life: 3.5, Compensation: 3.5, Culture: 3.1, Career: 3.5). The company has 15 active job postings, with a strong focus on senior AI researchers and software engineers.

## Sources
1. [Aleph Alpha Website](https://aleph-alpha.com/)
2. [Aleph Alpha Careers Page](https://jobs.ashbyhq.com/AlephAlpha)
3. [LinkedIn Company Profile](https://www.linkedin.com/company/aleph-alpha/)
4. [CB Insights Company Profile](https://www.cbinsights.com/company/aleph-alpha)

## Other roles at Aleph Alpha

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- [Senior AI R&D Engineer – Model Training  (f/m/d)](https://feeny.ai/job/senior-ai-r-d-engineer-model-training-f-m-d-aleph-alpha-heidelberg-xqr3y48gda71) — Heidelberg, Germany