Senior Machine Learning Engineer (Python/LLMs/NLP) - Hybrid Porto (Flexible Office Model)

ABOUT THE OPPORTUNITY

We are partnering with a fast-growing international technology startup building a next-generation AI-driven platform focused on intelligent automation, document processing, and large-scale data interpretation. As part of its expansion strategy in Portugal, the company is building a high-impact engineering hub in Porto and is looking for a Senior Machine Learning Engineer with strong Natural Language Processing expertise to join the founding technical team locally.

This is a unique opportunity to work directly with experienced founders and senior engineers coming from leading global tech companies and high-growth startups. You will play a critical role in shaping the architecture, scalability, and evolution of AI products from an early stage, while helping define engineering standards and technical culture.

The environment is highly dynamic, product-focused, and engineering-driven, ideal for professionals who enjoy ownership, autonomy, and solving complex technical challenges using modern AI technologies.

PROJECT & CONTEXT

The role focuses on designing, developing, training, evaluating, and deploying Machine Learning and AI capabilities at the core of the company’s platform.

You will work across the entire ML lifecycle, from data exploration and experimentation to production deployment and optimization, collaborating closely with backend engineers, product teams, and leadership.

Main responsibilities include:

• Designing and implementing NLP and LLM-based solutions
• Training and deploying Machine Learning models for intelligent document processing, classification, matching, and search
• Building scalable ML pipelines and evaluation frameworks
• Experimenting with modern AI tooling and state-of-the-art models
• Improving AI product reliability, performance, and safety
• Helping define AI engineering standards, tooling, and best practices
• Working in a fast iteration environment with strong product ownership

The technical environment includes modern AI/ML ecosystems, cloud-native infrastructure, and distributed engineering practices.

WHAT WE'RE LOOKING FOR (Required)

• 5+ years of experience in Machine Learning Engineering, Data Science, or AI-focused Software Engineering roles
• Strong experience with Python 3.x
• Hands-on experience with NLP and Large Language Models (LLMs)
• Experience with frameworks such as PyTorch 2.x, TensorFlow 2.x, Hugging Face Transformers, LangChain, or similar
• Strong understanding of model training, evaluation, fine-tuning, and deployment
• Experience building scalable ML pipelines and production-ready AI systems
• Experience working with vector databases, semantic search, embeddings, or retrieval systems
• Knowledge of cloud platforms such as AWS, GCP, or Azure
• Understanding of software engineering best practices, testing, CI/CD, and scalable architectures
• Experience working in startup or fast-paced product environments
• Strong communication and collaboration skills
• Fluent English (mandatory)

NICE TO HAVE (Preferred)

• Experience with agentic AI systems and multi-agent workflows
• Experience with Kubernetes, Docker, or MLOps tooling
• Knowledge of distributed systems and high-scale architectures
• Experience with data engineering workflows and modern data stacks
• Previous experience building AI products from scratch
• Experience in security-focused or compliance-heavy environments
• Familiarity with modern frontend/backend ecosystems such as React, TypeScript, or Node.js
• Portuguese language skills
• Experience mentoring engineers or helping scale technical teams