Principal Software Engineer

Principal Software Engineer

• Salary to £80k, poss higher for their ‘Unicorn’ candidate
• Role can be based remotely, as long as you can occasionally travel to London for client work. (travel expenses paid).

NB: Please only apply if you are a UK National, have resided in the UK for the past 5 years and are prepared to go through UK SC Security Clearance. Proof of ID will be required prior to interview.

This role is with a growing is a technology consultancy. This is a hands-on principal engineering role: architecture ownership across multiple services, technical leadership across teams, and direct contribution to engineering standards and hiring. Their successful candidate will be writing code as well as setting direction - this is not a purely architectural or management position. Current delivery is a Java/Spring Boot microservices platform on AWS EKS, with a Next.js frontend and Camunda-based process orchestration.

Essential

Experience level: 10+ years minimum, principal or staff grade equivalent.

Backend and cloud:

Java 17 or 21, at expert level - modern language features
Spring Boot in depth: security, transaction management, async/reactive
Microservices architecture design - has designed services from scratch
Kubernetes and Docker in production (not local development use)
AWS, hands-on: EKS, Lambda, S3, RDS, EventBridge
CI/CD pipeline ownership
Automated testing discipline: JUnit, Mockito, integration testing, TDD or BDD

Frontend:

Held a lead or tech lead role on frontend development in React. Leadership must have been over React work itself.
Understands and has implemented FFE/BFE separation - the split between the presentation layer (components, styling, client state) and the frontend's own server-side tier (data aggregation for the UI, session and auth handling, server-side rendering, API route composition).

Leadership:

Architecture ownership across multiple systems
Cross-team technical leadership
Track record of influencing engineering standards, technology choices, or hiring
Evidence of growing other engineers

Security clearance: UK SC clearance required. Active clearance strongly preferred; eligible candidates considered - must be a UK national with 5+ years continuous UK residency.

Desirable:

Camunda 8 / BPMN process orchestration
Next.js specifically (App Router, server components, route handlers)
Terraform or other infrastructure-as-code, to module-authoring level
React Native or equivalent — building native mobile from a React codebase
Design system or component library ownership
Consultancy or client-facing delivery background
Open-source contributions, conference talks, or published technical writing
Polyglot beyond Java

Other Stuff

NB: for non-UK Citizens; we cannot accept applications from anyone requiring sponsorship (now or in the future) for UK permanent employment status. If you are utilising a work visa this must allow you to work in the UK unrestricted for at least the next 5 years.

Profile 29 recruitment keywords: Java Spring Boot Microservices Kubernetes Docker AWS EKS Lambda S3 RDS EventBridge CI/CD Junit Mockito integration testing TDD BDD React Camunda BPMN Next.js Terraform lead senior manage manager director remote London hybrid developer engineer