Senior LLM Engineer: Training, Compression & Research

Multiverse Computing LLC; Barcelona; Hybrid; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Indefinite contract

Private health insurance

Hybrid opportunity

Flexible working hours

Language classes

Job summary

Multiverse Computing is seeking a Senior LLM Engineer to join the Research team. You will work across the full model lifecycle: data, training, post-training, compression, evaluation and efficient inference. Priorities shift in research, so strong fundamentals trump narrow specialisation.

We publish papers and release models when appropriate. Expect to train/post-train LLMs, design compression methods, build RL environments, and prototype innovative architectures.

Qualifications

• Master’s or PhD in Computer Science or related field, or equivalent experience.
• 4+ years of hands-on experience training or post-training transformer models.
• Strong PyTorch; comfortable with model code, losses and parallelism configurations.
• Experience with distributed training on multi-node clusters with Slurm/K8s.
• Hands-on post-training experience: SFT, DPO, and at least one RL method.
• Solid math foundations in linear algebra, optimization and probability.
• Good GPU fundamentals: memory hierarchy, mixed precision, profiling, throughput.
• Fluent English communication skills.

Responsibilities

• Train and post-train LLMs and multimodal models on multi-node GPU clusters.
• Design compression techniques and healing recipes for quality recovery.
• Build RL environments, reward functions and verifiers for reasoning and coding tasks.
• Research post-transformer and hybrid architectures from small-scale to scaling recipes.
• Build data pipelines for curation, filtering, and large-scale synthetic data.
• Design rigorous ablations and evaluations on benchmark suites and internal evals.
• Port and optimize models for inference on accelerators and edge chips.
• Write experiments and results as internal reports and papers/open-source releases.
• Review code and mentor teammates.

Skills

PyTorch

Distributed training

Debugging and communication

Fluent English

Education

Master’s or PhD in CS/AI/Math/Physics or equivalent

4+ years of hands-on transformer model experience

Tools

Slurm

Kubernetes (K8s)

Megatron-LM

DeepSpeed

Job description

Multiverse Computing is seeking a Senior LLM Engineer to join the Research team. You will work across the full model lifecycle: data, training, post-training, compression, evaluation and efficient inference. Priorities shift in research, so strong fundamentals trump narrow specialisation.

We publish papers and release models when appropriate. Expect to train/post-train LLMs, design compression methods, build RL environments, and prototype innovative architectures.