Software Engineer, AI Systems

Experienced Software Engineer, AI Systems – London or Copenhagen (Hybrid)

Software Engineer wanted for a growing technology business building large-scale data and measurement solutions for the global advertising and media industry.

A profitable and rapidly growing AdTech business is looking for an experienced Software Engineer to join its engineering function and help build the AI systems and agents being integrated into its products. This is a hands-on engineering role for someone with a strong software engineering and Computer Science foundation who has moved into AI and agentic systems.

You will work on production-grade AI infrastructure, building reliable and observable systems that can be trusted by customers, while applying strong software engineering principles around scalability, performance, security and reliability. You will work closely with experienced engineers, data scientists and product teams to determine where AI adds genuine value and how it should be implemented.

The role is available in London or Copenhagen, with a hybrid working setup.

The role:

* Build the infrastructure and AI harnesses that products use, including tool definition and injection, context assembly, orchestration, state and runtime control

* Develop and ship production AI components including agents, retrieval systems, runtime guardrails and fallback mechanisms

* Design how AI systems should operate, deciding where an LLM should make decisions and where deterministic code should control the system

* Build evaluation, tracing, monitoring and versioning capabilities to make AI systems predictable, measurable and reliable in production

* Contribute to the shared engineering foundations, infrastructure and patterns that enable engineers, data scientists and other teams to build with AI

* Work on complex technical problems involving large-scale data, distributed systems and AI, while considering performance, reliability, security, privacy and cost

You:

* Have 2+ years of professional software engineering experience, with a strong foundation in Computer Science, algorithms, system design and production software development

* Have experience building and maintaining production-grade software, ideally within backend, distributed, data-intensive or platform environments

* Have experience building AI, LLM or agentic systems, ideally beyond prototypes and into production

* Have a strong understanding of software engineering fundamentals, including testing, scalability, reliability, performance and how systems behave when individual components fail

* Have experience with areas such as AI agents, retrieval, tool calling, orchestration, evaluation, tracing or runtime guardrails

* Are a strong technical communicator who enjoys working within a collaborative engineering team, contributing to architectural decisions, reviewing code and sharing knowledge

* Experience in AdTech, measurement, analytics or data would be advantageous, while experience with languages such as Java, Scala, C#, Python or similar is welcome

Apply Now

You can apply for this role now by sending your CV to

Vanessa Wolf
Recruitment Consultant – Product and Tech UK and Europe
Sphere Digital Recruitment

Sphere Digital Recruitment currently have a variety of job opportunities across digital, so feel free to get in touch to find out how we can help you. Please visit our website for more information.

Sphere is an equal opportunities employer. We encourage applications regardless of ethnic origin, race, religious beliefs, age, disability, gender or sexual orientation, and any other protected status as required by applicable law.

If you require any adjustments or additional support during the recruitment process for any reason whatsoever, please let us know.

Sphere Digital Recruitment currently have a variety of job opportunities across digital so feel free to get in touch with us to find out how we can help you. Please take a look at our website.

If you require any adjustments or additional support during the recruitment process for any reason whatsoever, please let us know.