Principal Java Engineer - Backend Platform

Principal Java Engineer - Backend Platform

Salary: £76,340 - £100,340 Per Annum

Contract: Full-Time, Permanent

Location: Hybrid - minimum 2 days per week in office, Basingstoke/London/Bristol

About the Role

The Principal Software Engineer (Full-Stack, Backend-leaning) is a senior engineer responsible for the backend architecture, data pipelines, and API layer of a new sports technology product, while remaining capable of contributing to frontend development as needed. This role sits within a small, fast-moving product engineering team and requires someone comfortable owning end-to-end technical delivery across the stack, with backend and data work as the primary focus.

What You’ll Build

You will be a core contributor to a new backend platform being built from scratch. The work spans the full data journey - from ingestion at the edge through to storage, transformation, and delivery to end users. Key areas of focus include:

• Low-latency data pipelines that ingest and process live sports tracking data, with strict latency requirements for time-critical outputs delivered to coaches and analysts in near real-time.

• Event-driven processing using Kafka for streaming data and control messages between on-site devices and cloud services, handling both fast-path live outputs and asynchronous post-processing workflows via SQS and AWS Batch.

• Cloud infrastructure on AWS, including Greengrass for edge-to-cloud orchestration, S3 for video and data storage, and Lambda for lightweight processing tasks.

• Data transformation and aggregation layers that normalise tracking outputs, store them in a data lake, and make them available to downstream consumers via clean API contracts.

• REST and WebSocket APIs that serve both a live data product for immediate consumption and an insights portal for historical analysis and performance comparison.

• Observability and reliability - instrumentation, logging, and tracing are built in from the start, not bolted on. The platform needs to run ²⁴⁄₇ without on-site support.

Key Responsibilities

• Design and build backend services and APIs (REST/WebSocket) supporting data ingestion, transformation, and delivery to frontend and downstream consumers, with particular attention to latency and throughput given real-time processing requirements.

• Own data storage and pipeline architecture, including integration with streaming/event infrastructure.

• Implement authentication and authorisation in line with the team’s chosen cloud identity and access management approach.

• Provide technical direction and review for frontend development (React/TypeScript), working closely with frontend engineers to align on approach, component contracts, and data shapes - this is a collaboration and oversight function rather than day-to-day frontend delivery.

• Collaborate closely with computer vision/data science engineers to define and consume data contracts.

• Participate in technical decision-making for a product in active development, including architecture choices with long-term implications for scale, latency, and maintainability.

• Contribute to technical leadership of the wider engineering team, given the seniority of this role.

Skills and Experience

• Strong backend engineering background with production experience in Java (required).

• Demonstrated experience building low-latency, high-throughput systems - this is a core requirement, not a nice-to-have.

• Working knowledge of a modern frontend framework suc…