Principal Full-Stack Engineer

Php-Jobs; Greater London; Hybrid; GBP 100,000 - GBP 125,000; Full time

Job summary

A leading tech company in Greater London seeks a Principal Full-Stack Engineer with over 15 years of experience in building complex web applications. The ideal candidate will have significant expertise in PHP and modern JavaScript, and be proficient in cloud deployment and automated testing. This position offers a competitive contractor rate, flexible work arrangements, and access to global co-working spaces. Join us to engage in exciting technical challenges and drive innovation within the team.

Benefits

Competitive contractor rate

Top-Notch Workstation provided

Global Co-Working Access

Full flexibility in work location and hours

Participation in exciting events

Qualifications

• 15+ years of hands-on experience building complex web applications.
• Expertise in full-stack architecture, both legacy and modern.
• Extensive experience in automated testing, including TDD.

Responsibilities

• Manage complex engineering problems end-to-end.
• Build and enhance platform features.
• Engage in every phase of the software lifecycle.

Skills

Expert PHP developer

10+ years of modern JavaScript experience

Expert Linux user

Proficient with Symfony or equivalent frameworks

Clear technical communication

Tools

Docker

Terraform

Ansible

Job description

About Xcelirate

Xcelirate develops technologically-advanced platforms accessed by thousands of users every minute. We foster an environment where top developers collaborate to strategically plan and swiftly execute practices that maintain market dominance and drive global expansion. Our success is built on a decade of growth supported by our customers and talented team.

Principal Full-Stack Engineer

We are seeking a principal-level full-stack engineer—a seasoned expert who guides architectural decisions and remains deeply hands-on with the code. The ideal candidate approaches work with a stoic mindset, prioritizing clarity and importance over urgency, and naturally elevates the technical standards of those working alongside them.

You possess an intuitive understanding of advanced concepts like hot-path optimization, speculative execution, and lazy initialization. We encourage sharing details about personal homelab experiments driven purely by curiosity.

Key Responsibilities

• Manage time effectively while adhering to company priorities.
• Own complex engineering problems end-to-end, from problem framing and design through delivery and iteration.
• Ensure critical platform areas remain reliable, performant, and maintainable.
• Build new features and enhance existing ones across platforms.
• Pragmatically refactor legacy and modern codebases, balancing long-term health with delivery needs.
• Write comprehensive tests (unit, integration, and end-to-end) to ensure software reliability.
• Engage in every phase of the software lifecycle, from ideation to deployment.
• Participate in and occasionally lead deep technical discussions to drive sound decisions and trade-offs.
• Work hands-on across both backend and frontend systems.
• Identify inefficiencies and streamline workflows to reduce unnecessary effort.
• Collaborate closely with senior engineers, raising the technical bar through example.
• Take full ownership of work, ensuring high-quality, maintainable solutions.

Required Experience and Technical Skills

• Experience: 15+ years of hands-on experience building and maintaining complex web applications.
• Communication: Clear technical communication, capable of explaining and defending design decisions to both senior engineers and non-engineers.
• Backend Expertise: Expert PHP developer (12+ years), proficient with Symfony or equivalent frameworks.
• Frontend Expertise: 10+ years of modern JavaScript experience, including React or Vue (Next/Nuxt experience is a plus).
• Polyglot Skills: Expert level knowledge in at least one additional programming language (Python is a plus).
• Architecture: Expertise in full-stack architecture, including monoliths, services, and hybrid models.
• Cloud & DevOps: Power user experience in cloud deployment and scaling (AWS preferred).
• Linux & Containers: Expert Linux user, including daily containerized workflows with Docker.
• Infrastructure Automation: Expert proficiency in Terraform and Ansible.
• CI/CD: Power user level ownership of CI/CD pipelines and release workflows.
• Testing: Extensive experience in automated testing (unit, integration, E2E), including TDD where appropriate.
• Security: Expert knowledge of web security fundamentals: authentication, authorization, data protection, and secure coding.
• Codebase Fluency: Ability to work effectively on both legacy and modern codebases, focusing on incremental modernization.
• Ownership: Strong independent technical ownership and accountability.

Contractor Benefits and Support

• Competitive contractor rate of €85/hour plus a retention bonus scheme paid every 6 months.
• Top-Notch Workstation provided (latest MacBook, branded merchandise).
• Global Co-Working Access for dynamic and flexible work arrangements.
• Full flexibility in work location and hours to support work-life balance.
• Participation in exciting events and gatherings throughout the year (team gatherings, cultural events, etc.).