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Backend Symfony Developer

  • Employer: Citrus Systems
  • Contract type: Full-time
  • Location: Remote + part-time onsite (Belgrade, Serbia)
  • Salary: €3,000 – €6,000 / month (before taxes)
  • You must speak: English
  • Published on: August 6, 2025

Hello there, thanks for paying attention to our vacancy and let us introduce ourselves.

We are an IT company occupying a remarkable place in marketing, gaming, and financial segments of the iGaming industry. Our products are successfully implemented in European, African, and Latin American markets. Ever since we first started, we have been driven to find the best solutions in everything we do. At the same time, we have been creating strong connections all over the world which have helped us establish our presence in the industry. We strive for fun, elegance, and efficiency in everything we do. You can feel this in our relaxed, homelike working environment. We offer employment and seek to hire only the brightest, most driven, and most gifted minds around.

Currently, we are looking for an ambitious Senior PHP Developer to join our team for full-time employment in our beautiful office in New Belgrade.

Here are a few reasons to join us:

  • competitive salary and constant encouragement for your efforts and contribution (annual salary review); rapid growth (junior to CEO is a familiar journey for our company. We value business results and individuals eager to raise the bar. As an employer we provide supportive space to pursue your ideas);
  • we are taking care of the overall well-being of our people by providing private health insurance and Fit Pass for all;
  • work-life balance (every second week Power-Up Friday with 4 hours of working time, 25 working days of paid vacation, flexible schedule);
  • modern and comfy office (easy-to-get office in new business center with a spectacular view, free fruits, and snacks in the office, playroom with billiard, tennis table, and PlayStation);
  • we like to celebrate special days and have fun at our corporate events, and team-building activities, and we have special vouchers for our people's birthdays so you can enjoy your special day.

As a Senior PHP Developer you will tackle complex challenges. You will be deep in the codebase, taking ownership of critical backend components and shipping high-quality, impactful code. We believe that the best solutions are built together. This role offers significant autonomy, but it is firmly rooted in a collaborative environment. You will work in close collaboration with other engineers, product managers, and stakeholders, where your success will be measured not just by your individual code contributions, but by your ability to help the team make sound architectural decisions and elevate our collective standard of work.

Responsibilities:

  • Architecting & Developing: Design and build sophisticated, scalable, and maintainable backend features using Symfony.
  • API Mastery: Create, maintain, and document stable, fluent, and secure RESTful APIs that are consumed by our frontend applications and external partners.
  • Championing Quality: Lead by example with a rigorous approach to testing. You will write comprehensive unit, integration, and functional tests (PHPUnit) to ensure code is reliable and bug-free.
  • Database Expertise: Architect database schemas, write and optimize complex SQL queries in MySQL, and ensure our data layer is performant and robust.
  • Mentorship & Best Practices: Contribute to technical discussions, perform insightful code reviews, and help mentor other members of the team by promoting best practices.

Requirements:

  • Native or fluent Russian speaker, with professional working proficiency in English.
  • 5+ years of hands-on PHP development, with deep knowledge of the modern PHP ecosystem.
  • Expertise in Symfony, including core components like Doctrine, Twig, and Messenger.
  • A strong focus on quality and testing: You follow TDD/BDD principles and are confident with PHPUnit and Behat.
  • API development experience, including secure, scalable RESTful APIs, OAuth2/JWT authentication, versioning, and documentation via Swagger/OpenAPI.
  • Advanced SQL/MySQL skills, capable of designing performant schemas, writing complex queries, and optimizing with tools like EXPLAIN.
  • Comfortable working in Linux, using tools like grep, awk, and curl for diagnostics and service management.
  • Proficiency in Docker, including building clean Dockerfiles and managing multi-container environments with Docker Compose.
  • Experience with monitoring and observability, using tools such as Sentry, Kibana, Grafana, and profilers like Blackfire.

You also appreciate and actively use modern engineering tools to keep code quality high:

  • Static analysis with PHPStan
  • Code style enforcement using PHP-CS-Fixer
  • Automated refactoring with Rector

Bonus Experience (Highly Valued):

  • Marketing & Notification Systems: Hands-on experience with platforms like Customer.io or Optimove, and integrating with various SMS provider
  • APIs.Security & Fraud Prevention: Experience working with enterprise-grade security platforms like hCaptcha Enterprise or similar services.
  • AI-Assisted Engineering: You have experience thoughtfully integrating LLMs (e.g., Claude, Gemini, ChatGPT) into your development process. We are looking for a developer who leverages these tools not just for simple code completion, but for complex tasks like accelerating test creation, intelligent refactoring, and generating documentation. You understand how to apply them pragmatically to boost productivity and quality, while being mindful of their limitations.

Please apply with your CV and a link to your GitHub profile or a portfolio of your work. We look forward to seeing what you've built

From our part, we are ready to provide you with our full and comprehensive support in order to successfully cope with this list of tasks. Our CMS department is waiting for you to become an indispensable part of it!