Principal Backend Engineer

Salary: £55,000 - 95,000 per year

Requirements:

• Demonstrable experience in senior backend, data platform, or distributed systems engineering roles, with principal-level ownership across multiple services or teams
• Expert Python backend engineering, including API design, service boundaries, and async/concurrent systems, plus strong SQL and modern testing practices
• Hands-on Databricks / PySpark experience and lakehouse/medallion architecture, or equivalent large-scale data pipeline experience
• Strong AWS serverless background, including Lambda, API Gateway, S3, DynamoDB, and IAM, with infrastructure-as-code experience such as CloudFormation or SAM
• Deep understanding of multi-tenant SaaS design, authN/authZ, tenant isolation, secrets management, and operational security
• Experience designing stable data contracts and CLI/API/MCP contracts, including schema evolution and consumer-facing data models
• Proven technical leadership through mentoring, architecture decisions, code review, and clear trade-off communication without relying on direct authority
• Experience within the media, advertising, or similar industries

Responsibilities:

• Own backend and data architecture across pipelines, connector systems, platform APIs, agent/tool runtimes, CLIs, and downstream product surfaces
• Define durable domain boundaries and data contracts between warehouse outputs, operational stores, platform APIs, agent tools, and user workflows
• Lead the evolution of Databricks medallion pipelines, including ingestion, normalisation, and curated outputs for analytics and product use cases
• Improve data quality and governance through schema enforcement, lineage, documentation, and lakehouse-to-operational-store sync for consumer-facing data
• Architect Python backend services on AWS serverless paths, including authentication and tenant-scoped access patterns
• Shape how capabilities are exposed through OneSuite, including streaming workflows, tool permissions, MCP integrations, and stable CLI/API/MCP contracts
• Set engineering standards for testing, CI/CD, deployment safety, and observability
• Mentor senior engineers through reviews, pairing, and clear written guidance

Technologies:

• AI
• API
• AWS
• Lambda
• Architect
• Backend
• CI/CD
• Databricks
• Exposed
• IAM
• Marketing
• MCP
• Python
• PySpark
• SQL
• Security
• Serverless
• Spark
• Cloud
• Support

More:

We are Publicis Media, part of Publicis Groupe, harnessing the power of modern media through leading agency brands including Dysrupt, Infinite Roar, Publicis Collective, Publicis Health Media, Spark Foundry, Starcom, and Zenith, as well as global accelerator PMX, immersive experience group PMCI, and integrated platform-based technologies and offerings from CJ, Epsilon, and Influential. As a digital-first, data-driven global business, we deliver client value and drive growth in a platform-powered world. Performics is our Performance Centre of Excellence, building technology, data, and AI-driven marketing solutions for global brands. This is a hands-on principal-level individual contributor role shaping the backend and data foundation behind OneSuite, our unified marketing intelligence and automation platform, with a focus on enabling AI-assisted analyst workflows. We offer a wide range of benefits, including Pension, Life Assurance, Private Medical cover, Reflection Days, and Shared Parental Leave, along with access to inclusive benefits and Employee Action Groups. We work primarily from the office or our clients office four days per week. We are an equal opportunities employer committed to a fair, accessible, and inclusive recruitment process.

last updated 36 week of 2026