Hybrid Senior Machine Learning Engineer, Spain

at RemoteStar

• Job title: Senior Machine Learning Engineer, Spain
• Job type: Contract
• Experience level: Senior
• Salary: Not specified
• Degree requirement: Postgraduate Degree
• Tech skills: Numpy, Pandas, Python
• Location requirements: Hybrid, Barcelona, Spain

About the role

• Senior Machine Learning Engineer developing dataset strategies and model enhancements in a top-tier Quantum Software firm. Collaborating with a multicultural team to innovate in the AI domain.

Responsibilities

• Design and implement strategies for creating, sourcing, and augmenting datasets tailored for LLM training and fine-tuning.
• Develop scalable pipelines to collect, clean, filter, annotate, and validate large volumes of text data, ensuring quality, ethical compliance, etc.
• Collaborate with ML engineers, researchers, and software engineers to achieve ambitious goals in the preparation of LLMs and complementary work (preparing datasets, model evaluation, model serving, etc.).
• Develop and integrate new routines for modifying and enhancing LLMs, and extending their functionality.
• Make effective use of distributed compute resources and clusters (GPU’s), identify opportunities for further optimization.
• End-to-end preparation of compressed and specialized LLMs for use in production.
• Keep up to date with research trends in LLM foundation models, dataset curation, LLM pretraining data, and benchmarking.
• Contribute to building documentation, development standards, and a healthy shared code base.
• Mentor other engineers and provide knowledge sharing of cutting-edge techniques.

Requirements

• Master’s, or Ph.D. in Computer Science, AI, Data Science, Physics, Math, or a related field. Or equivalent industry experience.
• 4+ years of experience in data science, machine learning, or related roles, with demonstrated experience with NLP or LLMs.
• In-depth knowledge of large foundational model architectures (language and multimodal models) and their lifecycle: training, fine-tuning, alignment, and evaluation.
• Proficient in Python and data tooling ecosystems (Pandas, NumPy, Hugging Face Datasets & Transformers libraries).
• Hands-on experience with text data collection from diverse sources: web scraping, APIs, proprietary corpora, etc.
• Strong understanding of data quality metrics including bias detection, toxicity, and readability.
• Experience working in large shared distributed computing environments, familiarity with relevant tools for hardware optimization (vLLM, TensorRT, NeMo, etc.).
• Experience with version control (git), unit testing, and other fundamental aspects of software development.
• Effective communication and interpersonal abilities.

Benefits

• Two unique bonuses: signing bonus at incorporation and retention bonus at contract completion.
• Relocation package (if applicable).
• Up to 9-month contract, ending on June 2026.
• Hybrid role and flexible working hours.
• Be part of a fast-scaling Series B company at the forefront of deep tech.
• Equal pay guaranteed.
• International exposure in a multicultural, cutting-edge environment.