Senior Java Software Engineer

Principal Java Engineer - SaaS Architecture & Technical Leadership

• Location: Wallingford, Oxfordshire
• Salary: Highly Competitive - please apply to find out details
• Contract: Permanent, 37.5 hours per week

This is not a people-management position disguised as an engineering role.

Our client is looking for an accomplished Principal Java Engineer to take technical ownership of a business-critical SaaS platform used to help people navigate education, employment and the early stages of their careers.

Reporting directly to the CTO, you will shape the platform’s architecture, technical direction and engineering standards across multiple products and development teams.

You won’t have direct line-management responsibilities. Instead, you will lead through technical credibility, sound architectural judgement and the ability to help talented engineers solve difficult problems.

This is an opportunity to remain hands-on while having genuine influence over technology strategy, platform performance and the way software is designed and delivered.

What you’ll own

You will:

• Own the application architecture and technical direction across multiple products and services.
• Design, build and review high-quality Java solutions, APIs and integrations.
• Make architectural decisions that improve scalability, security, resilience and maintainability.
• Lead performance optimisation and platform-modernisation initiatives.
• Define and champion engineering standards, architectural principles and development best practices.
• Provide technical leadership across multiple Agile engineering teams.
• Translate product and business requirements into robust technical solutions.
• Remove complex technical blockers and identify delivery risks before they become problems.
• Conduct design and code reviews while remaining actively involved in development.
• Mentor engineers and raise technical capability without formal line-management responsibility.
• Lead root-cause analysis of complex production issues.
• Improve observability, monitoring, reliability and operational performance.
• Work closely with Product, Data, QA, DevOps and Operations teams.
• Embed secure software-development and OWASP principles throughout the engineering lifecycle.
• Explore how modern AI development tools can improve engineering quality and productivity.

The technology

The current technology environment includes:

• Java 21
• Spring Framework 6 and Spring Boot 3.5
• Hibernate ORM 6.6 and JPA
• Apache Tomcat 11
• REST APIs and OpenAPI
• Microservices and event-driven architecture
• RabbitMQ
• AWS, Docker, Kubernetes and Linux
• GitLab Pipelines and Jenkins
• MySQL and Apache Solr
• Logging, monitoring, metrics and observability tooling
• Angular and modern Node-based front-end technologies
• IntelliJ IDEA
• AI-assisted engineering tools including Claude, Codex and GitLab Duo

What we’re looking for

You will bring:

• Extensive professional Java engineering experience.
• Significant experience operating as a Principal, Staff, Lead or senior technical engineer.
• Expert knowledge of Java, modern language features and JVM performance.
• Deep experience with Spring Boot, Hibernate/JPA and enterprise application architecture.
• Strong knowledge of distributed systems, scalability, resilience and performance tuning.
• Experience building and operating cloud-native applications.
• Practical knowledge of AWS, Docker, Kubernetes and CI/CD.
• Strong understanding of application security, OWASP principles and secure development practices.
• Knowledge of a modern Node-based front-end framework such as Angular.
• Experience influencing architectural and technical decisions across multiple teams.
• The ability to communicate complex technical decisions clearly to both technical and non-technical stakeholders.
• A collaborative mentoring style and a genuine interest in helping other engineers improve.

A Computer Science degree is welcome, but equivalent professional experience is equally valued.

Why this opportunity?

This role offers:

• Direct access to and collaboration with the CTO.
• Genuine ownership of architecture and technical direction.
• A modern Java environment using Java 21 and Spring Boot 3.5.
• The opportunity to influence multiple products and engineering teams.
• Hands-on technical work without the burden of direct line management.
• The freedom to improve engineering standards, security and delivery practices.
• Access to modern AI-assisted development tooling.
• The chance to shape a meaningful SaaS platform with a clear social purpose.

Additional information

This is a permanent position working 37.5 hours per week, Monday to Friday, from 9:00am to 5:30pm.

The successful candidate will complete a three-month probationary period and appropriate background screening.

Our client is committed to building an inclusive workplace and welcomes applications from candidates with different backgrounds, experiences and perspectives.

If you are a senior Java engineer who wants meaningful architectural ownership while remaining close to the code, we would love to hear from you.

Apply now to find out more.