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