Senior ML Engineer (LLM)

Kiefer; Kentucky; Remote; USD 120,000 - 180,000; Full time

Benefits offered by this job

Remote work option

Relocation support

NVIDIA ecosystem access

Job summary

KIEFER is seeking a Senior Machine Learning Engineer to join Kiefer Tech and advance Sophea AI, a Greek-focused large language model. This role is hands-on, emphasizing LLM development, pre-training, training from scratch, fine-tuning, evaluation, and production-grade ML systems.

You will build production pipelines for inference and deployment, optimize GPUs, and work with datasets and benchmarks to improve model quality in a remote-friendly environment with relocation support to Athens.

Qualifications

• Hands-on experience with LLMs including pre-training and fine-tuning.
• Strong production ML experience and software engineering practices.
• Experience with model serving and deployment in production.
• Experience with GPU workloads and optimization.

Responsibilities

• Work on Sophea AI across pre-training, training from scratch, fine-tuning, evaluation.
• Build production-grade ML pipelines for inference, deployment, monitoring, and model lifecycle management.
• Optimize model performance in production focusing on latency, throughput and cost.
• Work with datasets, experiments, benchmarks to improve language model quality and domain-specific performance.

Skills

LLM development

Python

PyTorch

Production ML practices

Model serving

Inference optimization

GPU workloads

Tools

vLLM

SGLang

NVIDIA Triton

TensorRT

TGI

Job description

About the company:

KIEFER is building Greece's integrated AI ecosystem. From renewable energy infrastructure and AI systems to robotics and enterprise applications, we connect the technologies that power Europe's intelligent future. Founded in 2014, KIEFER has delivered 600MW+ of energy projects and is now developing sovereign AI infrastructure, enterprise AI products and physical AI systems for Greece and Southeast Europe.

About the role:

We are looking for a Senior Machine Learning Engineer to join Kiefer Tech and strengthen our ML Engineering team.

In this role, you will work on the development and continuous improvement of Sophea AI, our Greek-focused Large Language Model. You will be deeply involved in LLM pre-training, training from scratch, fine-tuning, model evaluation, inference optimization, and production-grade ML systems.

This is a hands‑on engineering role for someone who has already worked directly with language models and understands how to improve their quality, performance, and reliability in real production environments.

Important: this role requires strong practical experience with LLM development. Classical ML, computer vision, basic RAG, or high‑level AI tools alone will not be enough for this position.

What you will do:

• Work on Sophea AI across LLM pre-training, training from scratch, fine‑tuning, evaluation, and continuous model improvement




• Build production‑grade ML pipelines for inference, serving, deployment, monitoring, and model lifecycle management




• Optimize model performance in production, including latency, throughput, cost efficiency, quantization, and GPU workload usage




• Work with datasets, experiments, benchmarks, and evaluation methods to improve language model quality and domain‑specific performance

What you will need:

• Strong hands‑on experience with LLMs, including pre‑training, training from scratch, fine‑tuning, evaluation, and performance improvement




• Strong ML engineering background, including Python, PyTorch, Docker, and production ML practices




• Experience with model serving, inference optimization, quantization, GPU workloads, and frameworks such as vLLM, SGLang, NVIDIA Triton, TensorRT, TGI, or similar tools




• Ability to build production‑grade ML systems, not only research prototypes, scripts, basic RAG applications, or high‑level AI integrations

Nice to have:

• Experience with ASR systems, speech models, or speech‑to‑text pipelines




• Experience working with non‑English language models, multilingual models, or low‑resource language adaptation




• Experience with MLOps infrastructure, experiment tracking, model serving pipelines, and GPU workload management




• Contributions to open‑source ML projects or published research in AI/ML

What is there for you:

• Compensation: competitive package aligned with talent benchmarks




• Impact: hands‑on role working on Sophea AI, one of the most ambitious Greek‑focused AI products in the market




• Work format: remote work option, with relocation support available for candidates open to working from our Athens office




• AI‑native environment: real challenges across LLMs, training, fine‑tuning, inference optimization, GPU workloads, and production AI systems




• NVIDIA ecosystem: access to related conferences, certifications, internal knowledge sharing, and advanced AI infrastructure through Kiefer’s strategic collaboration




• Culture: engineering‑first, high autonomy, low bureaucracy, and space to build meaningful AI products