Principal Software Engineer - Java/Data Platforms

Principal Software Engineer is required for an innovative, well-funded early-stage renewable energy technology scale-up to lead the architecture and development of a new data platform while remaining hands-on with an existing Java-based SaaS platform.
Cambridge/hybrid, with remote work within the UK (with some team meetups).
This is an exciting opportunity for a strong Java Software Engineer with significant experience in data platforms, data engineering or modern data architectures, including Data Mesh, data pipelines and technologies such as Apache Iceberg.
You'll play a key role in shaping the technical direction of a growing business, combining greenfield platform architecture with hands-on software engineering and technical leadership.
Key skills required for the Principal Software Engineer

• Strong Java development experience, ideally Spring Boot or Micronaut, building scalable microservices and enterprise SaaS applications.
• Data Platform Architecture/Data Engineering - experience designing and building scalable data platforms, data pipelines or distributed data systems.
• Good working understanding of software architecture and design patterns, ideally within a Domain Driven Design (DDD) context.
• Opinionated on good practices around resilience, scalability and maintainability of large-scale software systems.
• Knowledge of Data Mesh, data lakes, lakehouse architectures or modern data processing patterns.
• Experience with technologies such as Apache Iceberg, Kafka, Spark, Flink or similar data engineering tools.
• Strong software architecture skills, including distributed systems, microservices and ideally Domain-Driven Design (DDD).
• Microservice networking and service meshes (such as Istio).
• Experience with Kubernetes, ECS, cloud platforms (AWS/GCP) and modern DevOps/CI/CD practices.
• Kafka and distributed systems
• Ability to provide technical leadership, influence architectural decisions and remain hands-on with development.

This is a Java-first engineering role requiring strong data platform expertise, rather than a pure Data Engineer or Data Architect position.
What you'll do as a Principal Software Engineer

• Lead the architecture, design and build of a new data platform, defining technical approaches and technology choices.
• Remain hands-on developing and enhancing the existing Java-based SaaS platform.
• Design scalable data pipelines, ingestion and processing capabilities using modern data engineering technologies.
• Shape the architecture of cloud-native microservices and distributed systems.
• Collaborate with product and engineering teams to translate requirements into robust technical solutions.
• Drive engineering best practices, code quality, testing and continuous delivery.
• Mentor engineers and provide technical leadership across the development team.

Why this role?

• Greenfield opportunity to architect and build a new data platform from the ground up.
• Java + Data Engineering - a varied role combining hands-on software development with modern data architecture.
• Join a well-funded, growing technology business following a recent $3m seed investment.
• Work with modern cloud-native technologies within a collaborative, technically driven engineering team.
• Make a genuine impact on technology supporting the renewable energy sector.
• Significant technical ownership and influence without moving away from hands-on engineering.

Opus Resourcing acts as an employment agency with respect to permanent employment.
Apply now or message us for more details. Referrals always welcome!