Senior AI Engineer

Addition; Greater London; On-site; GBP 20,295,000 - 24,908,000; Full time

Job summary

Addition is seeking a Senior AI Engineer to design, develop and operate large language model solutions in production. You will build platforms, pipelines and backend capabilities to deploy AI reliably at scale, blending machine intelligence with human judgement.

You'll work hands-on with Python, CI/CD (GitHub Actions), and AI observability tools, contribute to data platforms, integrate models in live environments, and collaborate across engineering, data and product teams.

Qualifications

• Experienced AI engineer with Python development skills and hands-on LLM design and operation.
• Strong production-level software development experience and backend integration knowledge.
• Familiar with AI observability and evaluation platforms and modern MLOps practices.

Responsibilities

• Design, develop and operate large language model solutions.
• Build production-ready AI applications and backend services.
• Develop scalable data platforms and supporting infrastructure.
• Integrate AI models and services into production environments.
• Establish monitoring, observability and evaluation for AI systems.
• Collaborate with engineering, data and product teams to translate requirements.

Skills

Python

LLM design

LangSmith

Braintrust

Arize

GitHub Actions

CI/CD pipelines

Observability

Education

Bachelor's or Master's degree in CS/AI/ML

Tools

GitHub Actions

CI/CD tooling

Job description

We're partnering with an innovative, technology-led organisation to appoint an experienced Senior AI Engineer.

This is an exciting opportunity to work at the forefront of AI and software development, designing and operating advanced large language model solutions and contributing to scalable, production-ready data platforms.

We're particularly interested in candidates who combine deep AI engineering knowledge with strong production-level software development skills and an understanding of how to integrate, monitor and evaluate AI systems effectively.

The Opportunity

As Senior AI Engineer, you'll play a pivotal role in designing, developing and operating large language model solutions within production environments.

You'll help build the platforms, pipelines and backend capabilities required to deploy AI reliably at scale, combining machine intelligence with human judgement to create practical and transformative solutions.

This is a hands-on technical position requiring someone who can solve complex engineering challenges, maintain high development standards and collaborate effectively within a dynamic, forward-thinking team.

Key Responsibilities

You'll play an important role in developing and scaling the organisation's AI capabilities by:

• Designing, developing and operating large language model solutions.
• Building reliable, production-ready AI applications and backend services.
• Contributing to the development of scalable data platforms and supporting infrastructure.
• Integrating AI models and services seamlessly into production environments.
• Developing maintainable, high-quality software using Python.
• Creating and managing CI/CD pipelines using GitHub Actions and related technologies.
• Implementing monitoring, evaluation and observability processes for AI systems.
• Supporting human-in-the-loop workflows and AI model-evaluation frameworks.
• Troubleshooting complex technical issues across AI applications, data platforms and deployment environments.
• Collaborating with engineering, data and product teams to translate business requirements into effective technical solutions.
• Maintaining strong standards across testing, documentation, version control and software delivery.
• Staying informed about emerging AI technologies, tools and engineering practices.
• Identifying opportunities to improve the performance, scalability and reliability of existing AI systems.

About You

You'll be an experienced AI engineer with strong Python development skills and significant hands-on experience designing and operating large language models.

You will also have:

• Extensive practical experience within AI engineering, particularly involving large language models.
• Strong proficiency in Python and production-level software development.
• Experience using LangSmith, Braintrust, Arize or similar AI observability and evaluation platforms.
• A strong understanding of LLM backend architecture and AI operations.
• Experience building data platforms and supporting scalable data infrastructure.
• Strong knowledge of GitHub Actions and CI/CD pipelines.
• Experience integrating AI models and services into live production environments.
• Strong analytical, problem-solving and troubleshooting skills.
• A proactive approach and the ability to work effectively within a collaborative team.
• The ability to communicate complex technical concepts clearly.
• The right to work in the UK, supported by verifiable documentation.

It would also be advantageous to have:

• Knowledge of human-in-the-loop systems and workflows.
• Experience deploying AI models within cloud environments.
• Programming experience with Java, C++ or another language in addition to Python.
• Previous experience building or operating AI systems at scale within an enterprise environment.
• Bachelor's or Master's degree in Computer Science, Artificial Intelligence, Machine Learning or a related discipline.

Why Apply?

This is a fantastic opportunity to make a direct impact within an innovative organisation developing the next generation of AI-enabled technology.

In return, you'll benefit from:

• A competitive rate of £475 per day.
• A senior, hands-on position with genuine technical influence.
• The opportunity to design and operate advanced LLM-based solutions.
• Exposure to modern AI evaluation, observability and data-platform technologies.
• The chance to solve complex production engineering challenges.
• A collaborative and forward-thinking working environment.
• The opportunity to help shape scalable AI systems with meaningful real-world applications.

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.