Mid/Senior AI LLM Engineer

Jobgether; Portugal; À distance; EUR 70 000 - 100 000; Plein temps

Avantages offerts par ce poste

Fully remote working arrangement in EU

Long-term collaboration with B2B

20 working days of paid leave

Health insurance allowance

Equipment budget for remote setup

Access to AI development tools

Learning & development support

Annual team gathering

Hands-on with self-hosted LLMs

Challenging technical environment

Résumé du poste

Jobgether is seeking a Mid/Senior AI LLM Engineer based in Portugal for a remote-first position. You will develop, fine-tune, and optimize self-hosted LLMs to power engaging AI conversations across multilingual scenarios.

You’ll work across data prep, training, and deployment, collaborating with cross-functional teams to deliver scalable solutions. The role emphasizes experimentation, evaluation, and production-ready improvements, with a focus on safety, performance, and user experience in

Qualifications

• Hands-on experience fine-tuning open-weight LLMs.
• Production deployment of ML models.
• Experience with SFT, LoRA, QLoRA.
• Familiarity with DPO/GRPO alignment methods.
• Experience with GPU-based training and infra debugging.

Responsabilités

• Fine-tune and optimize open-weight LLMs for quality and personalization.
• Prepare and curate training datasets to improve relevance and safety.
• Design evaluation frameworks to measure model quality and improvements.
• Enhance conversational memory and multilingual capabilities.
• Investigate failures and adjust data and prompts to fix issues.
• Run GPU-based experiments and optimize training workflows.
• Deploy improved models into production and monitor performance.
• Collaborate with teams to integrate AI into consumer products.
• Ensure responsible handling of sensitive content.

Connaissances

Python

PyTorch

HuggingFace

Fine-tuning

LoRA

QLoRA

SFT (supervised fine-tuning)

DPO/GRPO

Experimentation

Model deployment

Formation

Bachelor’s or higher in CS/ML

Outils

PyTorch

Hugging Face

Description du poste

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Mid/Senior AI LLM Engineer based in Portugal.

As a Mid/Senior AI LLM Engineer, you will develop, fine-tune, and optimize self-hosted large language models that power personalized, engaging AI conversations. You will work across the full model development lifecycle, from preparing training datasets and running GPU-based experiments to evaluating performance and deploying improvements into production. Your work will help enhance conversational quality, long-term memory, personality consistency, and multilingual interactions. Collaborating with AI engineers, product specialists, web developers, and DevOps teams, you will turn experimental findings into reliable, scalable solutions. This hands-on role offers the opportunity to work with open-weight models, advanced fine-tuning techniques, and practical AI evaluation frameworks. You will join a remote-first environment focused on building innovative, consumer-facing AI products while continuously improving model performance and user experience.

Accountabilities

• Fine-tune and optimize existing open-weight large language models to improve conversational quality, response accuracy, consistency, and personalization.


• Prepare, curate, and enhance training datasets to support effective model learning, reduce undesirable outputs, and improve the relevance and naturalness of generated responses.


• Design and implement evaluation frameworks, benchmarks, and testing methodologies to measure model quality, identify weaknesses, and validate improvements.


• Improve conversational memory, personality consistency, and the ability of models to maintain coherent, context-aware interactions over extended conversations.


• Develop multilingual conversational capabilities and support interactions involving multiple characters, ensuring natural and consistent behavior across different scenarios.


• Investigate model failures and performance limitations, adjusting training data, prompts, model configurations, and response filters to address identified issues.


• Conduct GPU-based training and fine-tuning experiments, troubleshoot infrastructure and performance issues, and optimize training workflows for efficiency and reliability.


• Apply modern model adaptation and alignment techniques, including supervised fine-tuning, LoRA, QLoRA, and preference-based optimization methods where appropriate.


• Deploy improved models into production environments, monitor their performance, analyze user-facing outcomes, and implement iterative refinements based on evaluation results.


• Collaborate with AI engineering, product, web development, and DevOps teams to integrate model improvements into consumer-facing applications and align technical work with product objectives.


• Work with sensitive conversational use cases and moderation requirements, balancing model behavior, user experience, and applicable content policies.

Requirements

• Proven hands-on experience fine-tuning open-weight large language models and deploying models into production environments.


• Strong Python programming skills, including experience developing, testing, and maintaining machine-learning workflows.


• Practical experience with PyTorch and Hugging Face or comparable machine-learning frameworks and model development tools.


• Experience with model training and adaptation techniques such as supervised fine-tuning (SFT), Low-Rank Adaptation (LoRA), and Quantized Low-Rank Adaptation (QLoRA).


• Familiarity with preference-based training and alignment techniques, such as Direct Preference Optimization (DPO) or Group Relative Policy Optimization (GRPO).


• Experience preparing and managing training datasets, improving data quality, and developing evaluation frameworks to assess model behavior and output quality.


• Practical experience with GPU-based model training, performance optimization, and debugging training-related technical issues.


• Strong analytical and problem-solving skills, with the ability to investigate model behavior, identify root causes, design experiments, and demonstrate measurable improvements.


• Understanding of the challenges involved in deploying and maintaining LLM-powered applications, including response quality, consistency, inference performance, and ongoing monitoring.


• Experience working on consumer-facing AI products, with an understanding of how model quality and conversational behavior affect user experience.


• Comfort working with minimally restricted or uncensored AI models, including explicit adult or NSFW content and sensitive moderation material, while applying appropriate safeguards and content-handling practices.


• Ability to work independently in a remote environment, manage experiments effectively, document findings, and collaborate with cross-functional teams.


• Strong communication skills, attention to detail, and a continuous-learning mindset, with the ability to translate experimental results into practical product improvements.

Benefits

• Fully remote working arrangement within Europe.


• Long-term collaboration opportunities, with B2B contracting preferred.


• 20 working days of paid leave.


• A monthly health insurance allowance of $100.


• Equipment budget to support your remote working setup.


• Access to AI development tools and technologies.


• Learning and development support to encourage continuous professional growth.


• Annual team gathering to connect and collaborate with colleagues.


• Opportunity to work hands-on with self-hosted LLMs powering innovative, consumer-facing AI products.


• A technically challenging environment offering exposure to modern language models, fine-tuning methods, and conversational AI development.