Senior Java Software Engineer

Our client, a software vendor in the security space, is seeking a Senior Software Engineer to design, build and run high-traffic Java services. This is a hands-on senior role: you’ll own features from design through on-call, set the standard for the engineers around you, and treat security as a design input rather than an afterthought.

What you’ll do

• Write production-ready code and own the pipeline and Helm chart that ship it
• Produce low-level designs other engineers can build from, and represent the team in architecture reviews
• Threat-model each feature, with authentication, authorisation and data handling designed in from the start
• Instrument before release, take a turn on call, and drive faults to root cause
• Spot technical gaps early, propose each fix with a cost and benefit, and use AI tooling day to day
• Mentor engineers, hold the line on testing and error handling, and interview candidates

What you’ll bring

• 8+ years with Java (including experience of Java 17+), Spring Boot and Spring Security, and the ability to debug the JVM from thread dumps, heap dumps and traces
• Experience designing and operating client-facing microservices, including API versioning and unit, integration, contract and load testing
• Designing for failure and scale: idempotency, retries, circuit breakers, caching, and data-led bottleneck diagnosis
• Strong relational data modelling and query design (MySQL), with schema and index tuning proven under load
• Solid security grounding: OWASP Top 10, authN/authZ, secrets management
• Kubernetes, Docker, Helm, AWS and CI/CD, including debugging failed deployments
• Clear design writing and a habit of reviewing peers’ designs

Nice to have: Reactive Java (WebFlux, Reactor, RxJava or Vert.x); telco/MNO integration experience; OAuth 2.0, JWT, SAML, FIDO or WebAuthn; work in a regulated industry; SLIs/SLOs and error budgets; Kafka in production; Terraform.