Principal AI Engineer in Belfast

We are expanding our global AI footprint and are looking for a passionate Principal AI Engineer to join Rapid7’s AI Centre of Excellence. You should be ready to provide technical guidance and mentoring to the team while understanding the trade-offs between technical, UX, and product needs. You should excel in interacting and negotiating with key stakeholders, leading to solutions that take all of these needs into account.

About the Team

The AI Centre of Excellence designs, prototypes, and ships production AI models and systems. Our mission is to leverage the best available technology to protect our customers’ attack surfaces. For example, we partner closely with Rapid7’s Detection and Response teams, including our MDR service, to leverage AI/ML for enhanced customer security and threat detection. We operate with a creative, iterative approach, building on over 20 years of threat analysis and a growing patent portfolio. The environment is collaborative, focused on knowledge sharing and continuous learning. If you’re passionate about AI and want to make a major impact in a fast-paced, innovative environment, this is your opportunity.

About the Role

The Principal AI Engineer is part of our AI Centre of Excellence team at the forefront of designing and delivering customer-focused AI systems. In this role, you will design and implement AI models and systems using the most appropriate techniques—conventional machine learning, deep learning neural networks, or generative and agentic AI. You will be working on a high-impact, cross-functional team, ensuring our AI solutions are scalable, secure, and deliver real customer value. Speed to market is key: you’ll operate in an agile, iterative way, making fast, informed decisions about what to build, what to pause, and where to innovate further. You will have the opportunity to further enhance your skills surrounded by an incredibly talented group of engineers and data scientists, while mentoring others and driving forward Rapid7’s AI innovation.

In This Role, You Will:

• Develop and ship AI systems with a focus on delivering customer value.
• Tackle a diverse range of complex problems, often reframing existing solutions with new perspectives.
• Take ownership of multiple projects as the principal go-to expert.
• Act as a first-class stakeholder throughout the AI R&D process.
• Build strong cross-functional relationships with engineering, UX, product management, and customer research teams.
• Mentor colleagues with less experience, acting as a trusted technical resource.

The Skills You’ll Bring Include:

• Significant hands-on experience in applied AI, able to independently design and build AI models and systems.
• Strong Python skills and practical expertise with:
• scikit-learn for conventional ML and data science.
• PyTorch, TensorFlow, or Keras for deep learning.
• AWS Bedrock, SageMaker, HuggingFace, or Transformers for LLM-based solutions.
• CrewAI (or similar frameworks) for agentic AI projects.
• Pandas/NumPy for data processing and transformation.
• Intuition for selecting the right models and approaches for different use cases.
• Cybersecurity expertise is a plus, but experience from other domains (e.g., finance, healthcare, marketplaces, insurance, legal, social media) is also highly valuable.

• Positive, can-do, solution-oriented mindset with persistence in tackling complex challenges.
• Bias for action and delivery, balancing speed with care.
• Ability to thrive in a fast-paced environment, juggling multiple projects effectively.
• Natural leader and collaborator, helping peers grow as problem solvers and communicators.
• Curiosity and passion for continuous learning and self-development.
• Open-minded approach, valuing feedback and new ideas from colleagues.
• Strong interpersonal and communication skills, with the ability to explain complex AI concepts to diverse audiences and document work clearly.