Principal Software Engineer – Java / Data Platforms

Opus Resourcing Ltd; Cambridge; Hybrid; GBP 90,000 - 115,000; Full time

Job summary

Opus Resourcing Ltd. is seeking a Principal Software Engineer in Cambridge. You will lead the architecture and development of a new data platform while staying hands-on with the Java-based SaaS platform, shaping the data-driven direction of the business.

The role combines greenfield data platform work with practical software engineering leadership, in a hybrid setup with UK-based remote options and team meetups.

Qualifications

• Strong Java development experience, Spring Boot or Micronaut is preferred.
• Experience designing scalable data platforms and data pipelines.
• Good understanding of software architecture and design patterns, ideally DDD.
• Knowledge of data mesh, data lakes, lakehouse architectures, and modern data processing.

Responsibilities

• Lead architecture, design and build of a new data platform.
• Remain hands-on developing the existing Java-based SaaS platform.
• Design scalable data pipelines, ingestion and processing using modern data engineering tech.
• Shape the cloud-native microservice architecture and distributed systems.
• Collaborate with product/engineering to translate requirements into robust solutions.
• Drive engineering best practices, code quality, testing and CI/CD; mentor engineers.

Skills

Strong Java development

Data Platform Architecture

DDD

Distributed systems

Cloud & DevOps

Tools

Apache Iceberg

Kafka

Spark

Flink

Kubernetes

Job description

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).

Salary £90-115k + Bens + Options

This is an exciting opportunity for a strong Java Software Engineer with significant experience in data platforms, data engineering or modern data architectures including some of 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.