Senior Machine Learning Engineer | up to €180k

Bluebird; Amsterdam; Hybrid; EUR 120,000 - 180,000; Full time

Benefits offered by this job

Relocation assistance

Visa support

Job summary

Bluebird in Amsterdam is building a world-class AI team focused on language models. You will train LLMs with continued pre-training and full fine-tuning on massive proprietary datasets, and you’ll design and optimize distributed training across multi-node GPU clusters.

You’ll generate synthetic data for instruction tuning and help shape evaluation frameworks that guide product decisions. The role combines hands-on coding with technical leadership, mentoring ML engineers, and making architecture

Qualifications

• 7+ years in ML engineering with production experience in language models or related models.
• Hands-on expertise in multi-node training, solving loss spikes and timeouts.
• Expertise in Python and PyTorch; experience with DeepSpeed and distributed training.
• Experience as a technical lead, mentoring engineers and delivering business-focused results.
• Nice to have: RLHF, vLLM, distillation, NeurIPS/ICML/ACL/EMNLP papers.

Responsibilities

• Train LLMs with continued pre-training and full fine-tuning on large proprietary datasets.
• Build and optimise distributed training on multi-node clusters (H200, DeepSpeed, FSDP).
• Own data at scale: filtering, deduplication, quality and data mixtures for corpora of 100B+ tokens.
• Generate synthetic data for instruction tuning and build evaluation frameworks.
• Lead the technical work: architecture decisions, code reviews and mentoring ML engineers.

Skills

ML engineering

Distributed training

Python

PyTorch

DeepSpeed

Mentoring

Education

Tools

DeepSpeed

NCCL

Megatron-LM

Transformers

Accelerate

Job description

Train the language models that millions of people use when they shop online. This AI team does more than call APIs. It does continued pre-training on 100B+ tokens of its own data, fine-tunes models, and puts them into production on its own GPU cluster.

About the company: who will you join?

• One of Europe’s largest consumer internet groups, with marketplaces and e-commerce companies that serve millions of users
• An in-house AI team that trains its own domain-specific LLMs, with models already in production
• Full support from senior leadership, up to the CEO. AI is the company’s top priority
• A team that is growing fast, with plans to build its own foundation models and a large increase in GPU capacity

About the role: what will you do here?

• Train LLMs with continued pre-training and full fine-tuning on large proprietary datasets
• Build and optimise distributed training on multi-node H200 clusters (DeepSpeed, FSDP, Megatron-LM)
• Own data at scale: filtering, deduplication, quality and data mixtures for corpora of 100B+ tokens
• Generate synthetic data for instruction tuning, and build the evaluation frameworks that guide decisions
• Lead the technical work: make architecture decisions, review code and mentor ML engineers

About you: what experience do you bring?

• 7+ years in ML engineering. You have trained language models and put them into production yourself (LLMs, encoders or embedding models)
• Hands-on experience with multi-node training. You know how to fix loss spikes, NCCL timeouts and slow throughput
• Expert in Python and PyTorch (Transformers, Accelerate, DeepSpeed)
• Experience as a technical lead. You make others better and focus on results for the business
• Extra points for: DPO/GRPO/RLHF, vLLM and distillation, papers at NeurIPS/ICML/ACL/EMNLP, or models and PRs on Hugging Face

Amsterdam, hybrid · Relocation and visa support