Senior AI R&D Engineer - Performance - Pre-training (f/m/d)

Aleph Alpha GmbH; Heidelberg; On-site; EUR 90,000 - 130,000; Full time

Benefits offered by this job

30 days vacation

Wellhub fitness & wellness offerings

Mental health support via nilo.health

Substantially subsidized pension plan

Germany-wide transportation ticket

Budget for additional technical equip.

Flexible working hours and hybrid work

JobRad Bike Lease

Job summary

Aleph Alpha GmbH in Heidelberg is seeking a Senior Performance Engineer to optimize training efficiency for foundation models on thousands of GPUs. You will profile, scale, and tune systems spanning software and hardware to maximize throughput and efficiency.

Join a team that blends deep learning, distributed systems, and GPU microarchitecture to remove bottlenecks while collaborating closely with researchers and engineers on-site in Heidelberg.

Qualifications

• Proficient in Python and PyTorch.
• Strong background in parallel and distributed systems.
• Experience with large language models and their lifecycle.
• Deep understanding of CUDA.
• Experience with NCCL or MPI.
• Experience analyzing profiling traces with PyTorch Profiler and Nsight.
• On-site collaboration in Heidelberg required.

Responsibilities

• End-to-End Optimization: profile training loops to maximize throughput.
• Distributed Strategy and Topology: tune composite parallelism and load balance for large-scale training.
• Hardware-Aware Modeling: collaborate with researchers to optimize architectures for hardware efficiency.

Skills

Python

PyTorch

Distributed systems

CUDA

NCCL/MPI

Profiling tools

Tools

Nsight Systems

Nsight Compute

PyTorch Profiler

CUDA toolkit

Job description

Our Mission

Aleph Alpha is one of the few companies in Europe doing serious foundation model pre-training like our recently released Kolibri-1 model. Our customers - in finance, manufacturing, public administration - need models that understand German, meet European regulatory requirements, and work reliably in high-stakes settings. We're building that in Heidelberg.

We are hiring a Senior Performance Engineer to grow our pre-training efficiency team. If you are excited about making models fast and scaling them to thousands of GPUs, this is the role for you!

Team Culture

At Aleph Alpha, we foster a culture built on ownership, autonomy, and empowerment. Teams and individual contributors are trusted to take responsibility for their work and drive meaningful impact. We maintain a flat organizational structure with efficient, supportive management that enables quick decision‑making, open communication, and a strong sense of shared purpose.

About the role:

You will engineer the systems required to train foundation models at scale. Your objective is to maximize hardware utilization and training throughput on our large-scale GPU clusters (thousands of NVIDIA Blackwell GPUs). You will work at the intersection of deep learning frameworks, distributed systems, and GPU microarchitecture, eliminating bottlenecks from the Python layer down to the GPU kernel.

This role is for Aleph Alpha Research GmbH.

Your responsibilities:

• End-to-End Optimization: Profile training loops using PyTorch Profiler, Nsight Systems and Nsight Compute to identify system- and kernel-level bottlenecks in order to maximize model throughput.

• Distributed Strategy and Topology: Configure and tune composite parallelism strategies (e.g. TP, DP, HSDP/FSDP, EP), optimizing load balance, minimizing critical‑path bottlenecks, and managing communication‑to‑computation trade‑offs for large‑scale LLM training.

• Hardware‑Aware Modeling: Partner with AI Researchers to define model architectures for hardware efficiency without compromising convergence.
  

Your Profile

Basic Qualifications

• Are proficient in Python and the PyTorch library.

• Have a strong engineering background in parallel and/or distributed systems with proven track record of excellence.

• Have hands‑on experience with modern machine learning techniques (especially large language models and their life cycle).

• Deeply understand the CUDA programming model.

• Have experience in distributed programming with APIs like NCCL or MPI.

• Have experience analysing profiling traces with tools such as PyTorch Profiler and Nvidia Nsight.

• Please note this role requires regular on‑site collaboration in Heidelberg as a member of the Training Efficiency Team.

Preferred Qualifications

• Contributions to modern distributed training frameworks (e.g., TorchTitan, Megatron‑LM, DeepSpeed).

• Familiarity with low‑precision training formats(MXFP4, MXFP8) and their impact on numerical stability and throughput.

• A deep understanding of NCCL communication primitives, NVSHMEM or CUDA IPC and their performance.

• A proven track record of implementing and optimising modern transformer‑based model training.

• A proven track record working on the NVIDIA Blackwell architecture.
  

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

• JobRad® Bike Lease