Senior Machine Learning Engineer – LLMs

ProsusAmsterdamHybridFull-time22 Sept 2026

Prosus is seeking a Senior Machine Learning Engineer to train domain-specific language models and provide technical leadership. The role involves owning critical training infrastructure, mentoring engineers, and driving technical decisions from data preparation through production deployment. Requires 7+ years of ML engineering experience with deep hands-on experience training language models at scale.

What you'll do

Analyze model performance and training data, formulate hypotheses, design and execute rigorous experiments to systematically improve model quality, training and inference efficiency, and downstream task performance
Drive technical decision-making for model architecture, training strategies, and infrastructure choices
Provide technical leadership and mentorship to ML engineers and interns, conducting code reviews, sharing best practices, and accelerating team growth
Train large language models through continued pre-training and full parameter fine-tuning on proprietary datasets
Build and optimize distributed training infrastructure across multi-node GPU clusters using frameworks like DeepSpeed, FSDP, Megatron-LM, or Axolotl
Own large-scale data preparation: filtering, quality assessment, deduplication, and data mixture strategies for training corpora at 100B+ token scale
Generate and curate high-quality synthetic data for instruction fine-tuning and capability enhancement
Debug training stability issues, optimize training and inference throughput (quantization, distillation, serving optimization), and monitor model performance throughout long-running distributed jobs
Build robust evaluation frameworks and establish metrics to measure model quality and guide decisions
Write production-grade, well-tested code and set engineering standards for the team

What you need

Must-have

PythonPyTorchTransformersDeepSpeedFSDPMegatron-LMAxolotlAccelerate

Nice-to-have

RLHFDPOGRPOReinforcement learningQuantizationModel compressionDistillationvLLM

Soft skills

Technical leadershipMentoringCode reviewsCommunicationExperimentationProblem solving

Machine LearningLLMsSeniorAIEngineeringTechnologyAmsterdamFull-timeOn-siteHybrid

/What you'll do

/What you need

Must-have

Nice-to-have

Soft skills

What you'll do

What you need