Sr. PHP Symfony Engineer

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About the Role
As a Senior PHP/Symfony Engineer, you will take hands-on ownership of backend development within a mature Symfony platform that manages marketing and revenue data for enterprise customers. The core application currently runs on Symfony 6.1, with an upgrade to Symfony 7 planned, alongside an Angular front end and TypeScript and Python AI agent microservices. This is a strongly backend-weighted, senior hands-on engineering role requiring an architect mindset, strong independence and the ability to understand how technical decisions affect the wider system. You will work within a remote, cross-functional product squad alongside engineering, product, QA and DevOps colleagues. Responsibilities
- Take ownership of backend development within the core Symfony application, becoming fully independent in delivering work within 2-3 months of joining
- Review and critically assess code written by the team and AI tools, challenging proposed approaches and making sure key considerations have been properly addressed
- Support the migration from Symfony 6.1 to Symfony 7 by resolving versioning, compatibility and legacy issues currently preventing the upgrade
- Improve the application’s performance, scalability and maintainability, making it easier and safer to introduce new functionality
- Work across the Angular front end, TypeScript and Python-based AI agent services, collaborating with DevOps where backend changes impact other areas of the system
- Be comfortable reading and understanding the Angular/TypeScript codebase, even though the role is primarily backend focused. Strong front-end development experience is not required
- Understand the wider impact of technical decisions across Symfony, Angular and AI services, while spotting gaps or issues in both human-written and AI-generated code
- Question existing approaches, identify root causes and look for better ways of building things rather than simply completing assigned tickets
- Deliver thoughtful, maintainable solutions within a legacy codebase while maintaining a consistent pace of delivery
- Work with a high level of autonomy and ownership while collaborating effectively with a remote, cross-functional team
- Follow SOC 2, PII and security requirements consistently and without exception Requirements
- 8+ years of commercial software engineering experience, including at least 5 years working with PHP
- 7+ years of Expert-level PHP development experience
- 3+ years of recent commercial experience with Symfony 6.x/7 at Advanced level. Strong senior-level Laravel experience may be considered where the experience is clearly transferable and the candidate has a good understanding of the differences between Laravel and Symfony
- 4+ years of Advanced experience in backend architecture, system design and scalability
- 2+ years of Advanced experience using AI development tools critically, including reviewing, validating and challenging AI-generated code rather than accepting it without question
- 5+ years of Advanced MySQL experience, including database schema design and query optimisation. Equivalent depth of experience with PostgreSQL or another relational database may also be considered
- At least 1 year of experience working with or understanding Angular/TypeScript. Experience with React or Vue using TypeScript may also be considered, but some front-end exposure is essential
- 3+ years of Advanced experience with automated testing using PHPUnit. Experience with Pest or another equivalent PHP testing framework may also be considered
- At least 1 year of Intermediate experience working on framework upgrades and modernising legacy codebases. Experience with major-version upgrades or significant refactoring in other large PHP applications may be considered
- 2+ years of Intermediate AWS experience. Equivalent experience with Azure or GCP may also be considered
- Fluent written and spoken English
- Strong written and verbal communication skills, with a demonstrated ability to work effectively in a remote environment
- Ability to work UK hours
- Ability t