Back End Developer

Robert Half Technology are assisting a leading UK media organisation to recruit a Backend Engineer on a 6–12 month contract.

We are hiring a Senior Backend Engineer to lead the evolution of a global platform supporting international expansion and acquisition integration.

This role focuses on building and scaling transaction systems that enable global commerce, while evolving an existing real-time platform to support new markets. You will address backend capacity constraints and help design a shared transaction and ledger layer used across multiple business lines.

This is a hands-on senior engineering role requiring both high-quality delivery and strong technical leadership in ambiguous, high-scale environments.

You will be expected to:

• Design scalable systems with correctness and failure modes considered from the outset
• Clarify and scope requirements before proposing solutions
• Make pragmatic trade-offs in system design, avoiding over-engineering
• Operate independently without reliance on AI tooling for core problem solving
• Fully understand, explain, and defend all systems and code you produce

Role

• The Backend Engineer will be responsible for designing and scaling systems supporting multi-currency, cross-border transactions
• Building and extending a shared transaction and ledger layer
• Supporting integration of newly acquired platform capabilities
• Designing APIs for frontend, mobile, and seller platform use cases (REST and GraphQL)
• Handling complex transaction logic including:
• Currency conversion
• Fees and commissions
• Reconciliation
• Refunds and adjustments
• Supporting region-specific requirements such as tax, shipping, and compliance
• Improving performance and scalability of real-time transaction systems
• Identifying bottlenecks and evolving platform architecture as demand grows

Profile

You will operate within a modern distributed systems environment spanning multiple services, languages, and architectural patterns. The role combines hands-on ownership of backend services with architectural leadership responsibilities.

• Elixir and the Phoenix framework
• GraphQL
• PostgreSQL
• Redis
• WebSockets and Phoenix Channels for real-time communication
• Message-driven architectures and asynchronous processing patterns
• Cloud-native infrastructure supporting globally distributed workloads

You may interact with services and systems built in:

• Python
• Go
• Java
• Kotlin
• C#
• TypeScript / Node.js
• Ruby
• Rust

API Design

• You will design, build, and consume:
• RESTful APIs
• GraphQL APIs

Company

• UK’s market leading media organisation with offices in London
• Hybrid working

Salary & Benefits

The salary range/rates of pay is dependent upon your experience, qualifications or training .