AI Engineer

Xelix; City Of London; On-site; GBP 65,000 - 75,000; Full time

Job summary

A growing AI solutions company in London is seeking a Mid-Level AI Engineer to develop cutting-edge technologies and enhance their products. The ideal candidate has 2-5 years of experience in machine learning, strong Python skills, and a collaborative mindset. You will work on impactful projects, enjoy a competitive salary, and benefit from a hybrid work environment with extensive leave options.

Benefits

Competitive salary of £65,000 to £75,000

27 days of annual leave

Hybrid working arrangements

Comprehensive private medical & dental coverage

Learning & development budget

Qualifications

• 2-5 years' experience delivering ML or LLM-powered features.
• Strong Python skills for AI/ML applications.
• Hands-on experience with gradient-boosted models.
• Solid data skills: SQL, pandas, and cloud deployment.

Responsibilities

• Design, train, and evaluate end-to-end ML models.
• Build applications leveraging large language models.
• Write clean, maintainable Python for AI/ML applications.
• Stay current with the latest AI/ML techniques.
• Collaborate with product, data, and engineering teams.

Skills

Machine Learning

Python

Collaboration

SQL

Gradient-boosted models

Job description

About us

At Xelix, we work with some of the world's largest companies to automate and strengthen their financial controls. Our AI solutions redefine how Accounts Payable teams operate - moving from manual processes to automated, intelligent workflows. Xelix is a fast-paced scale-up with ambitious growth. We aim to balance speed with profitability and invest in personal and professional growth. We celebrate milestones together and value ownership and impact.

In this role you'll grow, be challenged and help shape the future of Xelix. If you're excited about building something special with us, we'd love to hear from you.

About the role

We are now hiring for a Mid-Level AI Engineer to join our growing AI Engineering team. This role is an exciting opportunity to leverage state-of-the-art technology, including the latest LLMs and AI technologies, to power our tools and develop impactful new solutions for our customers.

What you'll be doing

• Model Development: design, train, and evaluate end-to-end ML models - from preprocessing to deployment - working with text, vision, and tabular data.
• LLM & AI Systems: build and refine applications leveraging large language models, prompt engineering, and agentic frameworks to solve real-world business problems.
• Production Code: write clean, maintainable Python for AI/ML applications and collaborate with our back-end team to integrate seamlessly into the platform.
• Experimentation & Research: stay current with the latest AI/ML techniques, test new algorithms and tools, and improve upon existing approaches.
• Collaboration: work closely with product, data, and engineering teams to deliver high-impact, customer-facing features.

What you'll bring

• 2-5 years\' experience delivering ML or LLM-powered features to production, from data prep and model training to deployment and iteration.
• Strong Python skills for AI/ML applications - clean, well-tested code, version control best practice, and smooth integration with back-end systems.
• Hands-on experience with gradient-boosted models (e.g., XGBoost, LightGBM) and/or building LLM-powered systems (e.g. tool/function calling, prompt design, evals) for text-heavy tasks.
• Solid data skills: SQL, pandas, experiment tracking, and cloud deployment (AWS a plus).
• A passion for AI/ML, shown through personal projects, a well-maintained GitHub portfolio, blog posts, or contributions to the AI/ML community.
• Strong collaboration skills - able to work closely with engineers, product managers, and data teams to ship impactful features.

What we offer in return

• Competitive salary of £65,000 to £75,000 depending on experience
• 27 days of annual leave (including 3 days Christmas closing), with the option to roll over 3 days
• Hybrid working with one day a week from our dog-friendly Hoxton office and on-site gym
• Comprehensive private medical & dental coverage with Vitality
• Enhanced parental leave pay
• Learning & development culture - £500 personal annual budget
• We\'re carbon-neutral and are working towards ambitious carbon reduction goals
• Lots of team socials & activities
• Annual team retreat

Want to learn more?

• About us
• Xelix blog
• Xelix news
• Xelix glassdoor

We believe that people from diverse backgrounds, with different identities and experiences make our company and product better. No matter your background, we\'d love to hear from you! And if you have a disability, please let us know if there\'s any way we can make the interview process better for you - we\'re happy to accommodate!

If you\'re a recruiting agency - we have an existing list of agencies we work with if required and we are not currently planning on expanding the list. Neither the Talent team nor hiring managers or the Support team will respond to cold outreach.

This is a full-time position, with standard working hours from 9:00 AM to 6:00 PM, Monday through Friday.

Interview Process

While the exact process may vary slightly depending on the role, our typical interview stages are:

1. Introductory Call - A short Teams conversation with a Talent Partner to discuss your background and the opportunity.
2. Hiring Manager Interview - A 30-45 minute Teams meeting to explore your experience and fit for the team.
3. Technical Task or Presentation - A role-relevant exercise to demonstrate your skills and approach.
4. Final On-site Interview - An in-person meeting with our senior leadership team and co-founders at our office.

We strive to make the process clear, efficient, and respectful of your time.