Lead Machine Learning Engineer, AI
Zaizi Open · verified Oct 22, 2026 At a glance
Senior Machine Learning Engineering role at Zaizi. London · no salary stated · we estimate £125,500–£152,500.
Zaizi has not published a salary for this role. The figure below is our estimate, not theirs.
aimlroles summary, based on the employer's posting.
What you'll do
- Build and deploy complex machine learning models, then check they meet quality, performance and scalability needs
- Choose suitable models for products and services, and adapt existing ones through tuning, retraining and maintenance
- Run MLOps pipelines for delivery, monitoring and retraining so deployed models operate reliably
- Investigate difficult machine learning issues and develop practical solutions to resolve them
- Prototype new AI applications, connect models to existing systems and check live models remain safe and effective
What you bring
- Strong machine learning expertise, including broad knowledge of algorithms, frameworks and established practices
- A track record of building, deploying and managing complex machine learning models
- You can work in the UK without sponsorship and have lived there continuously for at least five years
Who this fits
This senior role suits an experienced machine learning engineer who can guide technical decisions and mentor junior colleagues. The position is based in London and is described as hybrid, with UK work eligibility and continuous UK residence for at least five years required.
From the employer
Work on exciting public sector projects and make a positive difference in people’s lives. At Zaizi, we thrive on solving complex challenges through creative thinking and the latest tools and tech.
As a Machine Learning Engineer,AI, you’ll be responsible for researching, developing, and testing new AI algorithms, models, and technologies that businesses can use to automate tasks and gain insights from their data.
Key responsibilities include building complex models, designing and managing MLOps pipelines for CI/CD, monitoring, and model retraining. Mentoring junior members, influencing technical decisions within the team, and handling complex, non-routine problems.
Our work culture is inclusive, modern, friendly, and democratic. We look for bright, positive-thinking individuals with a can-do attitude. Our people enjoy challenging themselves to be the best at what they do – if that sounds like you, you'll fit right in!
Role Objectives
These are the expected objectives for this role. We are happy to discuss this further during the interview process with the successful candidate.
- Model Development & Delivery: Design, build, test, and deploy complex machine learning models, ensuring high standards of quality, performance, and scalabilityDecide what model is most suitable for use in products and services
- MLOps Pipeline Management: Design and manage robust MLOps pipelines, including continuous integration/continuous delivery (CI/CD), monitoring, and model retraining, to ensure efficient and reliable model deployment and operation
- Advanced Problem Solving: Act as a technical expert for complex, non-routine technical challenges within machine learning, developing and implementing innovative and effective solutions
- Customise, optimise, re-train and maintain existing models
- Deploy models into production, testing and assuring them to ensure they meet performance requirements
- Work with others to integrate models with existing systems
- Check that models used in live products and services stay safe, secure and continue to work effectively
Requirements
- Broad technical expertise in machine learning, demonstrating a deep understanding of various ML algorithms, frameworks, and best practices.
- Research. Plans and directs and carries out research activities, acting as a subject matter expert in generative AI research.
- Emerging Technology Monitoring. Systematically discovers and evaluates new generative AI technologies for business relevance, feasibility and relevance within the National Security Domain.
- Prototyping. Delivers complex, high-risk proofs of concept that test new AI applications.
- Specialist Advice. Serves as the primary source of expertise for generative AI within the organization.
- Data Science. Applies a range of data science techniques to support model development.
- Proven experience in building, deploying, and managing complex machine learning models.
SC Clearance:
Zaizi works with UK Central Government departments on a range of projects. To be able to work on our customer projects, employees must be Security Cleared to a standard acceptable to our Government customers. Due to this restriction we can currently only recruit candidates who have the right to work in the UK without sponsorship and who have lived in the UK for the last 5+ years continuously.
Benefits
Compensation
- Competitive Pay: Salaries reviewed annually to ensure they reflect your performance and market value.
- Loyalty Pension: We invest in your future. Starting at a 5% employer contribution, we increase this by 0.5% every year after your third anniversary, up to a maximum of 8%.
- Protection: Comprehensive Group Life Assurance for peace of mind.
Purpose & Culture
- Real Impact: Work on mission-critical projects that secure and improve the UK's digital infrastructure.
- Autonomy: A culture that empowers you to make decisions, prototype rapidly, and iterate towards success.
- Service & Community: We support those who serve. 10 paid days for Reservist Military Service.
Work / Life Balance
- Time Off: 25 days annual leave + Bank Holidays, with the flexibility to Buy/Sell additional days to suit your lifestyle.
- Giving back: 2 paid volunteering days per year.
Development & Growth
- Master Your Craft: Fully funded professional certifications (AWS, GCP, Agile, etc.) supported by 5 days paid study leave.
- Expand Your Horizons: An additional £500 annual "Personal Choice" fund to learn whatever inspires you—work-related or not.
- Support: Access to 1-2-1 professional coaching and team training to accelerate your career.
Health & Balance
- Premium Health: Vitality Private Medical Insurance (includes Apple Watch, gym discounts, and rewards).
- Flexibility: Genuine hybrid working with a WFH equipment allowance to perfect your home setup.
- Wellbeing: Cycle to Work scheme and a commitment to sustainable, healthy working practices.
For further information contact: talentteam@zaizi.com
Nat Hinds: Head of Talent
Kayla Kirby: Talent Acquisition Specialist