About this role

Kiosk mode

Senior Principal AI Engineer

R12604

Belfast, United Kingdom

Add to favorites

View favorites

Our Engineering organisation is scaling its AI Engineering capabilities under new leadership, creating an opportunity to shape the next generation of AI at Rapid7. We’re looking for Senior Principal AI Engineers to define and influence the technical direction of our LLM and agentic AI systems across the organisation. You’ll tackle our most complex technical challenges, establish architectural principles and engineering standards, and drive greenfield innovation that delivers meaningful impact for our global customers. Through technical leadership and mentoring, you’ll shape strategic product and platform investments and influence how we build and scale AI across Rapid7.

About the Team

AI is reshaping cybersecurity on both sides. Attackers can use AI to strike at machine speed, and only AI-powered defense can keep up. At the same time, organizations can only adopt AI with confidence if it is secure. Rapid7 sits at the intersection of security and AI, and we are building industry-defining products for this new era.

Rapid7's AI Engineering team builds the AI that powers our security platform. We are AI engineers and applied scientists who take models from research to production, combining open-source and frontier LLMs, AI agents, and fast predictive models with more than 20 years of Rapid7 security expertise. Our work drives core use cases across Detection and Response, such as alert triage, threat investigation, and automated response, and Exposure and Remediation, such as vulnerability prioritization, attack surface risk assessment, and guided remediation. Together, these help customers stop threats faster and fix what matters most.

About the Role

As a Senior Principal AI Engineer, you will set the technical direction for how Rapid7 builds, tunes and serves LLMs and agentic systems across its security products. You understand LLMs from the ground up, from transformer internals and training to fine-tuning and inference optimization, and you stay hands-on with the hardest problems. You know where LLMs shine and where they fall short, and you treat them as one tool in the AI toolbox, alongside predictive AI and classical ML, choosing the right approach for each problem. Specifically your focus will be to:

Set the AI technical vision, architecture and multi-year roadmap for LLM and agentic systems across Detection and Response and Exposure and Remediation
Define company-wide model strategy, including when to use frontier or open-source models, when to fine-tune, distill or post-train, and where to invest in new capabilities
Lead the most complex and highest-risk technical initiatives across multiple teams, including fine-tuning, distillation and post-training of open-source LLMs on security data
Establish company-wide standards for context engineering, inference optimization and evaluation, with evals as the release gate for every AI system we ship
Lead optimization of LLM inference at scale, balancing quality, latency and cost
Lead design reviews, resolve the most complex technical trade-offs, and stay hands-on by prototyping and building critical model, training and inference code
Mentor and develop Principal, Staff and Senior engineers, building the depth of AI engineering talent across Rapid7
Represent Rapid7’s AI engineering to executives, customers and the external community, influencing product, platform and business strategy

The skills and qualities you’ll bring include:

14+ years of software or ML engineering experience, including 2+ years building production LLM or agentic AI systems. A PhD in Computer Science, Machine Learning, AI or a related field is preferred, or equivalent depth of expertise demonstrated through industry experience and technical contributions
A track record of building scalable, production-grade AI systems and shared platforms adopted across multiple products, with company-wide impact through technical leadership, mentoring and standards
Leading-edge expertise in LLMs, including transformer architecture, attention, tokenization and positional encodings, and how models are trained and served, with advanced PyTorch skills spanning custom model code, mixed precision and distributed training (e.g., FSDP, DeepSpeed)
Hands-on fine-tuning and post-training of open-weight LLMs, including full and parameter-efficient methods (LoRA, QLoRA), distillation, and preference or RL-based methods (e.g., DPO, GRPO), ideally including experience training LLMs from scratch
Deep experience with context engineering (retrieval, memory, and context management for long-running agent workflows) and with defining evaluation strategy and benchmarks for LLM and agent systems
Deep knowledge of inference optimization, including prefill and decode, KV-cache management, continuous batching, speculative decoding and quantization, and serving at scale with vLLM, SGLang or TensorRT-LLM, ideally on AWS and including GPU kernel work (CUDA or Triton)
Strong predictive AI, classical ML, distributed systems and Python fundamentals, with the judgment to make efficient, transparent decisions between these approaches and LLMs based on accuracy, latency and cost
Takes accountability for organisation-wide technical outcomes, proactively addressing systemic risks and removing barriers to delivery while ensuring technical decisions align with strategic priorities
An influential communicator who can articulate complex architectural trade-offs, build consensus and influence technical and product decisions across the organisation
Builds alignment across Engineering, Product and other functions on technical direction, driving decisions that shape product and platform investments.
Anticipates evolving customer needs and shapes AI architecture and technical strategy to maximise customer value, making informed trade-offs between capability, performance, cost and scalability to guide product and platform investment
Thrive in ambiguity at the leading edge of AI, driving change and focusing forward as the technology and the threat landscape evolve
Recognition as an expert in AI, evidenced by publications, patents, open-source contributions or industry engagement
Embody our core values to foster a culture of excellence that drives meaningful impact and collective success.

We know that the best ideas and solutions come from multi-dimensional teams. That’s because these teams reflect a variety of backgrounds and professional experiences. If you are excited about this role and feel your experience can make an impact, please don’t be shy - apply today.

LI-CG1

About Rapid7

At Rapid7, our vision is to create a secure digital world for our customers, our industry, and our communities. We do this by harnessing our collective expertise and passion to challenge what’s possible and drive extraordinary impact. We’re building a dynamic and collaborative workplace where new ideas are welcome.

Protecting 11,500+ customers against bad actors and threats means we’re continuing to push the envelope just like we’ve been doing for the past 20 years. If you ’re ready to solve some of the toughest challenges in cybersecurity, we’re ready to help you take command of your career. Join us.

Security and Compliance Rapid7 is committed to keeping customers secure. As a first line of defense, all employees are expected to uphold the highest standards of security and privacy, ensuring the protection of sensitive information and compliance with relevant regulations.

Apply Now

First Name (required)

e598291f

Last Name (required)

e9da5224

Email (required)

6501425e

Apply

Please wait...

Done

Not You?

Application loading...

Job Alert

202cbc68

Finalize your job alert by selecting criteria from the dropdowns below. You can select multiple options from each dropdown by returning to the combobox and re-entering the list of options. Submit at the end to create your job alert.

Departments

Product & Engineering

Locations

Belfast, United Kingdom

First Name (required)

e5bcdfc9

Last Name (required)

4e39b1bd

Email (required)

f7cbcc8b

Send

Please wait...

Done

Not You?

Thank you

Jobs you may be interested in

Account Executive, Canada

Canada

Rapid7’s Canadian Sales organization is seeking a Toronto-based Account Executive to join the team. Serve as a strategic partner for clients across the assigned geography, helping organizations achieve a more secure digital future. Drive critical ...

Workplace Facilities Coordinator

Arlington, VA, United States

Rapid7 is seeking an energetic and organized Workplace

Experience

Coordinator to support daily operations and elevate employee and visitor experiences in a fully onsite model at our Arlington, VA office. In this role, you will coordinate core faci...
Senior Principal AI Engineer
Dublin, I