Sr. PHP Symfony Engineer (Remote, Full-Time) [AR024]

About Smart Working At Smart Working, we believe your job should not only look right on paper but also feel right every day. This isn’t just another remote opportunity — it’s about finding where you truly belong, no matter where you are. From day one, you’re welcomed into a genuine community that values your growth and well-being. Our mission is simple: to break down geographic barriers and connect skilled professionals with outstanding global teams and products for full-time, long-term roles. We help you discover meaningful work with teams that invest in your success, where you’re empowered to grow personally and professionally. Join one of the highest-rated workplaces on Glassdoor and experience what it means to thrive in a truly remote-first world. Applicants must have the right to work in the country they are applying from and be able to work without employer sponsorship. 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 to successfully complete strict background checks and adhere to PII and data protection requirements. - Strong self-sufficiency, with the ability to operate independently and without handholding after 2–3 months, while continuing to collaborate effectively with the wider team. - A hands-on engineering approach combined with an architectural mindset, with the ability to understand how and why the wider system works rather than focusing only on writing code. Nice to Have - 2+ years of Intermediate CI/CD experience with GitHub Actions; GitLab CI, Jenkins or Azure DevOps are suitable alternatives. - Basic experience with Amazon Redshift or data warehousing; Snowflake or BigQuery may be considered. - Azure exposure alongside AWS. - Previous project leadership experience. - Previous mentoring and technical leadership experience with other engineers.