Principal Java Engineer - Retail

Mindera; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Benefits offered by this job

Six month contract outside IR35

Opportunity to work with leading UK‑r?

Competitive rates

Friendly team

Job summary

Mindera is seeking a Principal Java Engineer with strong Retail experience to lead backend initiatives, architect scalable services, and mentor the engineering team. The role is a six-month contract outside IR35 in London (Paddington), with on-site presence three days a week and a focus on Java 17+, Spring Boot or Micronaut, Kafka, and cloud-native delivery on Azure.

You will collaborate with product owners and engineers to influence decisions, improve reliability, security, and cost-efficiency

Qualifications

• Proven experience as a Principal Java Engineer in backend-heavy environments with multiple engineering levels.
• Strong experience in Java 17+ and Spring Boot or Micronaut; Kotlin is a bonus with willingness to learn.
• Hands-on knowledge of Kafka and event-driven architectures, enterprise integration patterns, and microservices.
• Solid understanding of payment systems and PSP integrations, including fraud, tokenisation, and settlement flows.

Responsibilities

• Lead technical deep dives and knowledge sharing; anticipate challenges and propose solutions.
• Influence product and business decisions across teams.

Skills

Java

Java 17+

Spring Boot

Micronaut

Kafka

Event-driven

Azure

Kubernetes

CI/CD

DevOps

Agile/Scrum

Communication

Tools

Terraform

OpenTelemetry

Dynatrace

GitHub Actions

Job description

At Mindera, we craft software with people we love. We're looking for a Principal Java Engineer with strong Retail experience who can join our crew!

Please note: This is a six month contract that sits outside IR35. You will be required to work in Paddington 3 days a week.

What does the role involve?

• Lead technical deep dives and knowledge sharing in the teams, anticipating challenges and proposing solutions
• Start influencing product and business decisions

Hands-on Software Development:

• Write high-quality Java code using frameworks such as Spring Boot or Micronaut
• Build robust services that support secure, high-volume payment transactions
• Develop integrations with acquiring banks, payment gateways, and fraud detection tools

Cloud & DevOps Practices:

• Build and support cloud-native systems on the cloud (preferably Azure) using Terraform and Kubernetes
• Manage CI/CD pipelines using GitHub Actions and ensure smooth delivery to production
• Own monitoring, alerting, and observability, using tools like OpenTelemetry and Dynatrace

Security & Compliance:

• Champion secure coding practices and data protection across services

Collaboration & Mentoring:

• Work closely with product owners, engineering leads, and other stakeholders to shape technical solutions
• Mentor and support more junior/mid/senior engineers, driving technical excellence across the board
• Help establish and promote best practices around code review, testing, delivery, and operational support

Continuous Improvement:

• Continuously improve platform reliability, performance, and cost-efficiency
• Stay up-to-date with technology trends and proactively identify innovation opportunities

Requirements

• Proven experience as a Principal Java Engineer in backend-heavy environments in teams having multiple levels of engineering
• Strong experience in Java 17+, ideally with experience in using Spring Boot or Micronaut. Kotlin experience is a bonus. If the applicant does not have experience they must show willingness to learn Kotlin
• Hands-on knowledge of Kafka, event-driven architecture, enterprise integration patterns and Microservices
• Solid understanding of payment systems and PSP integrations, including fraud, tokenisation, and settlement flows
• Experience with cloud infrastructure (Azure preferred), CI/CD, and Kubernetes
• Working knowledge of regulatory and compliance standards (PCI DSS, SCA, PSD2)
• Strong communication skills and the ability to explain complex technical concepts to a range of audiences
• Experience working in Agile/Scrum teams with a DevOps culture and test-driven mindset

Benefits

• Competitive Rates
• Six month contract outside IR35 with possibility of extension
• Friendly and welcoming team
• Opportunity to work with one of the UK's leading Retailers

At Mindera we use technology to build products we are proud of, with people we love.

Software Engineering Applications, including Web and Mobile, are at the core of what we do at Mindera. We partner with our clients, to understand their product and deliver high performance, resilient and scalable software systems that create an impact on their users and businesses across the world.

You get to work with a bunch of great people, where the whole team owns the project together. Our culture reflects our lean and self-organisation attitude. We encourage our colleagues to take risks, make decisions, work in a collaborative way and talk to everyone to enhance communication.

We are proud of our work and we love to learn all and everything while navigating through an Agile, Lean and collaborative environment.

Check out our Blog and our Handbook

Mindera around the world: Porto, Portugal | Aveiro, Portugal | Coimbra, Portugal | Leicester, UK | San Diego, USA | San Francisco, USA | Chennai, India | Bengaluru, India | Blumenau, Brazil | Cluj-Napoca, Romania | Valencia, Spain | Casablanca, Morocco & Remote.