Senior Software Engineer in London

We go beyond the obvious, using intelligence, passion and creativity to inspire new thinking and shape the world we live in.

As a Senior Software Engineer in our Digital Twins Division, you’ll help build the systems behind one of Kantar’s most ambitious AI products. Your work will enable thousands of AI‑driven “digital twins” to simulate real‑world consumer behaviour in real time, giving brands powerful insight into complex decisions.

This isn’t a traditional full‑stack role. You’ll focus on scalable backend systems, event‑driven architectures, and AI‑enabled platforms, working closely with product, data science and platform teams to turn advanced AI capabilities into reliable, production‑ready systems. Your work will directly shape how clients interact with data and insights at scale.

What you’ll be doing

• Designing and building technology that can grow with our ambition, including:
• Creating scalable, distributed backend services for AI‑driven applications
• Building event‑driven systems that process large volumes of behavioural data in real time
• Developing services in Node.js/TypeScript and/or Python
• Designing APIs that support high‑throughput, low‑latency workloads
• Helping orchestrate and optimise AI agent‑based systems running at scale

You’ll also contribute to technical direction, mentor others, and help us continuously improve how we build and operate our platforms.

The skills & experience you’ll bring

You don’t need to tick every box, but experience in several of the following will set you up for success:

• Strong backend engineering experience with cloud‑based systems (Azure, AWS or GCP)
• Experience designing distributed or event‑driven architectures (Kafka or similar)
• Proficiency in TypeScript/Node.js and/or Python
• Experience building scalable APIs and microservices
• Working knowledge of containers and cloud‑native delivery approaches
• Curiosity about AI‑enabled systems and how they scale responsibly
• Experience with LLMs, AI agent orchestration, or tools such as RAG, vector databases or LangChain is a bonus, but not essential.

What’s in it for you

• Flexible hybrid working
• 25 days leave, 2 days paid for volunteering and life event leave
• Competitive salary and bonus (bonus dependent on role)
• Company pension
• Enhanced parental leave
• Healthcare options
• Wide range of flexible benefits

We are not able to offer visa sponsorship or assist with relocation support for this role. Please ensure you have the right to work in the country where this role is located before applying.

At Kantar we have an integrated way of rewarding our people based around a simple, clear and consistent set of principles. Our approach helps to ensure we are market competitive and also to support a pay for performance culture, where your reward and career progression opportunities are linked to what you deliver.

We want to create an equality of opportunity in a fair and supportive working environment where people feel included, accepted and are allowed to flourish in a space where their mental health and well being is taken into consideration. We want to create a more diverse community to expand our talent pool, be locally representative, drive diversity of thinking and better commercial outcomes.

Kantar is the world’s leading data, insights and consulting company. We understand more about how people think, feel, shop, share, vote and view than anyone else. Combining our expertise in human understanding with advanced technologies, Kantar’s 30,000 people help the world’s leading organisations succeed and grow.