Senior Software Engineer | Python

We’re the world’s leading data, insights, and consulting company; we shape the brands of tomorrow by better understanding people everywhere.

Kantar’s Profiles division is home to the world’s largest audience network.

With access to 170m+ people in over 100 global markets, we offer unrivalled global reach with local relevancy. Validated by industry leading anti-fraud technology, Kantar’s Profiles Audience Network delivers the most meaningful data with consistency, accuracy, and accountability – all at speed and scale.

Job Details

We’re the world’s leading data, insights, and consulting company; we shape the brands of tomorrow by better understanding people everywhere.

About the job

We are looking for a Senior Backend Engineer to join our growing engineering team. In this role, you will work on both internal platforms and client‑facing services, building scalable, secure, and high‑performance backend systems that operate on a global scale!

You will primarily work with Python, FastAPI, and modern cloud‑native architectures, designing and developing APIs that sit in front of AI‑powered and data‑driven products.

A key part of the role will involve migrating data science and machine‑learning workloads into robust, maintainable, and engineering‑compliant services and infrastructure.

You will collaborate closely with data scientists, product managers, and other engineers to translate analytical and AI capabilities into reliable backend services. As a senior engineer, you will help shape technical direction, influence architectural decisions, and ensure that systems meet high standards for reliability, performance, and maintainability.

Job Goals

Backend Development

• Take technical ownership of one or more backend services, from design through to production and ongoing operation.

• Drive design and architecture decisions for backend services, balancing short‑term delivery with long‑term maintainability.

• Review and improve existing codebases, identifying opportunities for refactoring, simplification, and performance improvements.

• Set and promote best practices for Python service structure, dependency management, and API design.

Data & Persistence

• Ensure data consistency, reliability, and scalability across services.

• Design database schemas and write efficient queries aligned with application requirements.

AI & Platform Integrations

• Build backend support for AI‑powered features such as text analysis, classification, summarisation, or automation.

• Design scalable and observable integrations with external APIs and internal analytics systems.

• Collaborate with data science and product teams to operationalise advanced analytical and AI‑driven use cases.

Leadership & Team Contribution

• Mentor and support other engineers through code reviews, pairing, and technical guidance.

• Lead by example in writing clear, maintainable, and well‑tested code.

• Contribute to hiring activities such as technical interviews and onboarding of new engineers.

• Help shape team processes, ways of working, and technical standards.

Collaboration & Communication

• Contribute to technical design discussions and architecture decisions.

• Strong written and verbal communication skills for presenting findings to stakeholders.

Ideal Skills & Capabilities

Backend & Python Skills

• Deep understanding of Python internals, performance characteristics, and common pitfalls in production systems.

• Strong experience with async Python (e.g. asyncio, async FastAPI patterns) and knowing when not to use it.

• Experience structuring large Python codebases with clear boundaries, shared libraries, and versioning strategies.

• Proven ability to design testable, maintainable Python services, with a strong emphasis on automated testing and code quality.

• Experience evolving Python APIs and services without breaking downstream consumers.

• Practical experience managing Python projects with Poetry, including dependency resolution and packaging.

Platform Modernisation & Migration

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