We are seeking a highly experienced Software Engineer to lead the design, development, and fdelivery of mission-critical financial systems on a modern Microsoft Azure and SQL Server technology stack. In this role, you will partner directly with business stakeholders, subject matter experts, and cross-functional teams to analyse complex financial problems and translate requirements into scalable, high-performance software solutions. As a senior member of the development team, you will take ownership of the end-to-end development lifecycle—from architecture and design through coding, testing, deployment, and ongoing support—ensuring that our business-critical applications meet the highest standards of quality, reliability, and maintainability.
The ideal candidate will have strong experience in data modelling, system integration, data migration, data integrity and financial systems, with a deep understanding of or willingness to learn about billing workflows.
A Proven track record of delivering high-performance, low-latency, and secure applications in fast-paced environments.
Software development experience in Java with a proven track record in designing, developing, testing and maintaining large-scale financial systems. You will collaborate with cross-functional teams, including business analysts, architects, QA, and other developers, to deliver robust, scalable, and secure software solutions for a critical financial application.
· Competitive salary: £75,000 – £80,000 per year
· Company pension, life insurance and sick pay
· Cycle-to-work scheme and on-site parking
· Monday to Friday schedule, so your weekends are all yours
· Partner with the Principal Engineer and Team to drive technical excellence across Java Spring based microservices.
· Provide technical guidance and mentorship to engineers, promoting industry and team best practices in software design, coding standards, testing, and code reviews.
· Support architectural decision-making by contributing to the design of scalable, resilient, and maintainable solutions.
· Lead the implementation of complex technical features and help resolve high priority production incidents.
· Champion engineering best practices, including CI/CD, automated testing, observability and secure software development.
· Engage directly with finance, risk, and operations stakeholders to gather, validate, and prioritise business requirements.
· Translate complex financial calculations, data flows, and regulatory requirements into clear technical specifications and user stories.
· Present architectural approaches, trade-offs, and progress updates to both technical and non-technical audiences.
· Collaborate with Principal Engineer and Team to continue to evolve the Azure Microservice architecture, ensuring the solution is scalable, maintainable, secure and fault tolerant
· Contribute to Principal Engineers roadmap for technical enhancements, capabilities and future feature development.
· Support design of new API’s, Service integrations and creation of data models within the Castle Water domain.
· Support technical discussions and “on-the-spot” mentoring by giving guidance to less experienced engineers throughout the course of architectural design and implementation.
· Champion code quality through automated unit, integration, and performance testing.
· Embed security best practices (authentication, authorisation, encryption, secrets management) into application design.
· Monitor and optimise application performance, leveraging Azure Monitor, Application Insights, and SQL Profiler.
· Bachelor’s or Master’s degree in Computer Science, Engineering, or related field.
· Proven experience in the development of financial systems.
· Strong understanding of billing operations, data mapping, and regulatory compliance.
· Excellent project management, problem-solving, and communication skills.
· Strong proficiency with Java and Spring Boot
· Strong proficiency in Front End and Back End Development
· Strong proficiency with Angular, Node.js, and TypeScript.
· Strong proficiency with cloud platforms (Orchestration tools such as but not limited to Bicep, Terraform, ARM)
· Proficiency with ETL tools such as Azure Data Factory, databases (SQL), and system integration technologies.
· Strong proficiency with Unit and Regression Testing
· Strong professional experience in financial systems.
· Solid understanding of asynchronous programming and event-driven architecture
· Experience with version control systems like Git and Git workflows
· Experience with data structures, algorithms, and design patterns.
· Experience with security best practices, such as secure API and data protection.
· Exposure to testing automation tools such as Junit and Selenium
Castle Water is redefining the utilities sector as one of the fastest-growing and most successful companies in the UK. Guided by our core values of fairness, transparency, tenacity and being supportive, we deliver outstanding service to a diverse range of customers, including some of the UK’s largest companies and public sector organisations.
We believe in putting people first. Whether it’s creating positive interactions with our customers or fostering a supportive workplace culture, our commitment to fairness and transparency ensures we build lasting relationships with our customers.
With over 20,000 5-star Trustpilot reviews, our reputation is built on trust and excellence. We tackle every challenge with tenacity and a dedication to doing what’s fair and right.
Our head office in Blairgowrie, Perthshire, is located within easy reach of Perth and Dundee. As a company embedded in the local community, we actively participate in events that reflect our supportive values. We also have offices in Brentford, London, and Ayr, offering plenty of opportunities to join our growing team.
If you’re looking for company that’s dynamic, forward-thinking and values-driven, Castle Water is the place for you.
Hannah Bodie
Onboarding Manager
We’re committed to making the process as smooth and accessible as possible. If you need any additional support or reasonable adjustments, please let us know. You can reach us by calling 01250 718700 or emailing [email protected].
