Senior Backend Engineer in London

About the Department

Performics is the Performance Centre of Excellence within Publicis Groupe, delivering technology, data, and AI-driven marketing solutions for global brands. OneSuite is our unified marketing intelligence and automation platform powering agentic workflows, data processing, analytics services, and channel automation across Search, Social, Programmatic, Commerce, and Measurement. Backend engineering is foundational across all OneSuite - providing the APIs, integration layers, orchestration runtimes, and backend systems that power every charter, from Agent Studio to AOE, DFP, Channels, and SRE.

About the Role

We are seeking a Senior Backend Engineer (Individual Contributor) to lead the design, development, and evolution of backend systems across OneSuite. This is a hands-on engineering role - you will write production-grade code, solve complex distributed systems problems, shape backend patterns, and guide other engineers through technical influence (not supervision). As a Senior IC, you will help define service architecture, enforce engineering best practices, and collaborate across multiple charters to ensure OneSuite's backend systems are scalable, reliable, secure, and performant.

Responsibilities

• Backend Architecture & System Design
  • Architect distributed backend services and APIs using Python, FastAPI, Node.js, or equivalent frameworks.
  • Design modular, observable, and scalable backend components for orchestration, data services, and platform integrations.
  • Define patterns for microservices, domain boundaries, caching, queuing, resiliency, and error handling.
  • Build robust service-to-service communication mechanisms (REST, gRPC, event-driven patterns).
  • Implement secure authentication, authorization, rate limiting, and multi-tenant access controls.
• Hands-On Backend Development
  • Write high-quality, maintainable, production-ready code.
  • Integrate with external APIs (marketing platforms, cloud services, internal microservices).
  • Build and maintain CI/CD pipelines and infrastructure-as-code environments.
  • Lead code reviews, mentor engineers, and ensure high engineering standards.
  • Contribute to platform SDKs, internal libraries, and backend frameworks used across charters.
• Performance, Reliability & Observability
  • Implement tracing, structured logging, metrics, dashboards, and alerting.
  • Optimize services for latency, concurrency, throughput, and cost efficiency.
  • Ensure system reliability through automated testing, load testing, error budgets, and resiliency strategies.
  • Partner with SRE to define SLIs/SLOs and improve platform-wide reliability.
• Cross-Functional Collaboration
  • Work closely with Studio, AOE, DFP, Channel, and SRE teams on shared backend designs.
  • Collaborate with Product Managers and UX research teams to translate requirements into backend capabilities.
  • Align architecture decisions across charters to ensure consistency and maintainability.

Qualifications

• Demonstrable backend engineering experience, with architectural ownership over services or distributed systems.
• Expertise in Python, FastAPI, Flask, or Node.js and modern backend development patterns.
• Strong understanding of microservices, concurrency, async programming, and event-driven architectures.
• Proficiency with SQL and NoSQL databases (PostgreSQL, DynamoDB, Redis, MongoDB).
• Hands-on experience with Docker, Kubernetes, and cloud platforms (AWS or GCP).
• Strong CI/CD experience using GitHub Actions, Jenkins, Argo, or similar tools.
• Deep knowledge of observability practices - logs, metrics, traces, performance analysis.
• Proven ability to write clean, testable, well-structured production code.

Qualifications - Nice to Have

• Experience with streaming or queuing systems (Kafka, Pub/Sub, SQS).
• Familiarity with AI/LLM systems (AOE integration), though not required across all charters.
• Knowledge of data engineering patterns or ETL/ELT workflows.
• Prior experience with API gateway architectures, caching layers, or service meshes.
• Exposure to cybersecurity best practices and secure service design.

Additional information

Publicis Groupe has fantastic benefits on offer to all of our employees. In the UK, in addition to the classics, Pension, Life Assurance, Private Medical and Income Protection Plan, we also offer; WORK YOUR WORLD opportunity to work anywhere in the world, where there is a Publicis office, for up to 6 weeks a year. REFLECTION DAYS - Two additional days of paid leave to step away from your usual day-to-day work and create time to focus on your well-being and self-care. HELP@HAND BENEFITS 24/7 helpline to support you on a personal and professional level. Access to remote GPs, mental health support and CBT. Wellbeing content and lifestyle coaching. FAMILY FRIENDLY POLICIES We provide 26 weeks of full pay for the following family milestones: Maternity. Adoption, Surrogacy and Shared Parental Leave. FLEXIBLE WORKING, BANK HOLIDAY SWAP & BIRTHDAY DAY OFF You are entitled to an additional day off for your birthday, from your first day of employment. GREAT LOCAL DISCOUNTS This includes membership discounts with Soho Friends, local restaurants and retailers in Westfield White City and Television Centre. Full details of our benefits will be shared when you join us!

Publicis Groupe operates a hybrid working pattern with full time employees being office-based three days during the working week. We are supportive of all candidates and are committed to providing a fair assessment process. If you have any circumstances (such as neurodiversity, physical or mental impairments or a medical condition) that may affect your assessment, please inform your Talent Acquisition Partner. We will discuss possible adjustments to ensure fairness. Rest assured, disclosing this information will not impact your treatment in our process.

Please make sure you check out the Publicis Career Page which showcases our Inclusive Benefits and our EAGs (Employee Action Groups).