Senior ML Engineer (Token Factory)

Jobgether; España; Híbrido; EUR 90.000 - 130.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Competitive pay

Flexible work environment

Learning opportunities

Global team

Impactful projects

Descripción de la vacante

Partner Company is seeking a Senior ML Engineer (Token Factory) based in Spain to lead large-scale ML infrastructure projects. You will build inference and fine-tuning technologies for foundation models across language, vision, audio, and multimodal architectures.

You will collaborate with experienced engineers and researchers in a fast-moving, international environment, turning research ideas into production-ready systems with strong software practices.

Formación

• Strong foundation in machine learning and reinforcement learning.
• Experience training large ML models across multiple nodes.
• Proficiency with Python and modern DL frameworks (JAX).
• Exposure to CI/CD, version control, testing, and production-grade software engineering.

Responsabilidades

• Develop and improve fine-tuning methodologies for foundation models including LoRA and full-parameter approaches.
• Optimize model quality and training efficiency at large scale.
• Address bottlenecks in LLM inference for production efficiency.
• Build training/evaluation pipelines using JAX (speculative decoding, advanced inference).
• Experiment with model architectures (dense, mixture-of-experts, autoregressive, parallel).
• Develop scaling laws to guide model development and resource allocation.
• Investigate low-precision training/inference (FP8, NVFP4, MXFP4).
• Work with distributed training across multiple GPUs/nodes.

Conocimientos

ML fundamentals

Reinforcement learning

Distributed training

Python

JAX

CI/CD

English communication

Research to production

Herramientas

JAX

Python

Descripción del empleo

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior ML Engineer (Token Factory) based in Spain.

This role offers the opportunity to work at the forefront of large-scale AI infrastructure and machine learning systems.

You will help build inference and fine-tuning technologies for foundation models spanning language, vision, audio, and multimodal architectures.

Your work will focus on improving model quality, training efficiency, inference performance, and hardware utilization at massive scale.

You will tackle technically challenging problems involving distributed training, low-precision computation, optimization, and reinforcement learning.

Working primarily with Python and JAX, you will turn advanced research ideas into reliable, production-ready systems.

The role combines deep technical ownership with opportunities to influence engineering practices and contribute to the evolution of AI platforms.

You will collaborate with highly experienced engineers and researchers in a fast-moving, international environment where your work can have significant impact.

Accountabilities

• Develop and improve advanced fine-tuning methodologies, including LoRA-based and full-parameter approaches, for cutting-edge foundation models.
• Optimize model quality and training efficiency across large-scale machine learning workloads.
• Identify and address bottlenecks in large language model inference to improve production performance and resource efficiency.
• Build training and evaluation pipelines using JAX for techniques such as speculative decoding and advanced inference optimization.
• Experiment with different model architectures, including dense and mixture-of-experts models as well as autoregressive and parallel approaches.
• Develop and evaluate scaling laws to inform model development, performance optimization, and resource allocation.
• Investigate low-precision training and inference approaches, including FP8, NVFP4, and MXFP4, for supervised fine-tuning and reinforcement learning.
• Work with distributed training environments spanning multiple computational nodes and large GPU clusters.
• Analyze performance considerations such as sharding strategies, custom kernels, and modern hardware capabilities.
• Translate research concepts and experimental results into robust, scalable, production-quality machine learning systems.
• Apply strong software engineering practices, including CI/CD, version control, unit testing, and maintainable code design.
• Collaborate across engineering and research teams while communicating technical concepts clearly and contributing to technical direction.

Requirements

• Deep understanding of the theoretical foundations of machine learning and reinforcement learning.
• Strong expertise in modern deep learning techniques for language processing and generation.
• Demonstrated experience training large machine learning models across multiple computational nodes.
• Solid understanding of performance optimization for large neural network training, including sharding strategies, custom kernels, and hardware-specific capabilities.
• Strong software engineering skills, particularly with Python.
• Extensive experience with modern deep learning frameworks, particularly JAX.
• Proficiency in contemporary software development practices, including CI/CD, version control, unit testing, and production-quality engineering.
• Strong communication, collaboration, and technical leadership abilities.
• Experience working with language models or related NLP technologies is highly valued.
• Familiarity with concepts such as multi-head attention, RoPE, ZeRO/FSDP, Flash Attention, and quantization is advantageous.
• Experience building and delivering products in dynamic, startup-like environments is a plus.
• Strong engineering background in distributed systems or high-load web services is beneficial.
• Open-source projects demonstrating advanced engineering capabilities are valued.
• Excellent English communication skills, including strong technical writing and articulation.

Benefits

• Competitive compensation.
• Career growth and continuous learning opportunities.
• Flexible working environment with a high degree of ownership.
• Opportunity to work on impactful, large-scale AI and machine learning projects.
• Collaborative culture with experienced engineers and researchers.
• International environment with diverse and highly skilled teams.
• Opportunity to contribute to advanced foundation model training, fine-tuning, inference optimization, and AI infrastructure.
• Exposure to cutting-edge GPU computing, distributed systems, and modern machine learning technologies.

Inclusive workplace committed to equal employment opportunities.

Support and reasonable accommodations throughout the hiring process when required.