Principal Machine Learning Engineer, ExTrac

£140-180k

AWS

Python

PyTorch

Senior and Expert level

London

2 days a week in office (Liverpool Street, London)

We combine human expertise, curated data, and domain-specific AI to enable faster decision-making.

Open for applications

We combine human expertise, curated data, and domain-specific AI to enable faster decision-making.

21-100 employees

B2BArtificial IntelligenceSecurityBig dataMachine LearningSaaS

Open for applications

£140-180k

AWS

Python

PyTorch

Senior and Expert level

London

2 days a week in office (Liverpool Street, London)

21-100 employees

B2BArtificial IntelligenceSecurityBig dataMachine LearningSaaS

Company mission

To empower our customers to make faster, better-informed decisions about the risks and opportunities emerging from world events.

Job

Company

Role

Who you are

8+ years of experience in ML engineering, with deep domain expertise in LLMs, NLP, and Transformer architectures
Proven success putting ML / NLP systems into production in fast-paced startup environments ideally from 0 to 1
Strong coding skills in Python, with experience building and optimising ML pipelines using tools like PyTorch, JAX, Ray, or similar
Experience with retrieval-augmented generation (RAG), vector stores, prompt engineering, and fine-tuning on custom data
An independent, product-minded thinker who thrives in ambiguity and can drive complex projects from conception to launch

What the job involves

Architect and implement robust, scalable systems for training, fine-tuning, and serving large language models (LLMs)
Drive end-to-end development of NLP features, entity recognition, summarisation, classification, RAG, and beyond
Lead initiatives in evaluating and optimising model performance, latency, and cost across GPUs/TPUs and CPU inference stacks
Partner cross-functionally with engineering, product, and DevOps teams to ship ML-backed features that directly impact customers
Establish best practices for model versioning, experimentation, observability, and safety in production environments
This is an individual contributor (IC) role, you will not be required to line manage any team members
We're still early, which means your work will shape the direction of our ML systems, infrastructure, and product. You'll work with a small, mission driven team that values clarity, pragmatism, and speed and you’ll ship things that matter

Application process

1. CV Review & Discussion of Role
2. Python Pair Programming Session
3. Machine Learning System Design
4. Competency Based Questions

Salary benchmarks

Our take

Traditional intelligence gathering often struggles to keep pace with the evolving nature of threats. Siloed approaches focus solely on physical or online risks and miss the complex interplay between the two, leaving organisations vulnerable.

ExTrac offers a comprehensive approach, with its system bridging the physical and online divide, providing real-time insights into a broad range of threats, including terrorism, violent extremism, disinformation, and crime. Its Co-Analyst tool allows even non-experts to obtain valuable insights and make faster, more informed decisions.

The company's innovative technology and focus on user-friendliness positions it to empower a wide range of organisations to proactively manage risk. As the threat landscape continues to evolve, ExTrac is poised for continued growth, with a wealth of opportunity on its horizon.

Freddie

Company Specialist at Welcome to the Jungle

Company

Employee endorsements

Meaningful work

"We are driven by an inspiring mission to support customers engaged in real-world security and threat management on a daily basis. ExTrac is leading..."

Browse all endorsements

Company benefits

Flexible working: work where you work best, with the opportunity to spend two days a week working with the team in person
Access to our central London office space
The opportunity to develop and take on new challenges and responsibilities as we grow as a company
An annual individual learning and development budget of £500

Company values

Creativity & Design | We blend technology and human understanding to create solutions that are both powerful and intuitive.
Innovation & Excellence | We don’t follow the crowd – we pursue excellence and push boundaries at every turn.
Products That Are Loved | We build with purpose, obsess over the details, and take pride in everything we create.
No Egos | We push hard, own our mistakes, and succeed together.

Company HQ

City of London, London, UK

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