We at Holycode are currently looking for a full-time, experienced, and highly skilled Senior Backend Developer to join the Function 365 team. In this role, you will be responsible for designing, developing, and maintaining a large-scale application, as well as building and integrating back-end systems using GraphQL, JavaScript, Node.js, and MySQL.

About Function 365

F365 is the market leader in providing a comprehensive electronic healthcare record solution for private clinics providing preventive and longevity medicine. F365 is trusted by hundreds of healthcare professionals across the UK, EU and USA. Through strategic and meaningful customer relationships F365 provides a continually evolving system to manage all aspects of running private healthcare organisations. F365 is a growing team of young vibrant, dedicated professionals and we fully embrace modern remote working. We're interested in the outcome of your efforts, not how many hours you’ve been in the office.

What You’ll Do

Design, Develop and maintain GraphQL APIs for internal and external consumption
Develop and maintain API integration of the F365 application with 3rd party API services
Write clean, well-documented, and testable code using industry-standard coding practices.
Participate in code reviews and provide guidance to junior developers.
Implement tests (Unit, integration)
Refactoring and bottleneck optimizing
Participating in setting up CI/CD processes
Implementing monitoring (Grafana)

Requirements

Direct experience with GraphQL API design, implementation and upgrade
Direct experience with RESTful API implementation, and upgrade
4+ years of relevant experience MySQL
Strong knowledge of JavaScript and PHP
Good knowledge of Symfony 6.x and MDB
Experience with Relational DB
Strong direct experience with integration of external API’s from other projects you’ve worked on
Strong direct experience with developing internal API for internal and external consumption
Knowledge of common accepted software design principles (design patterns, anti-patterns,
refactoring, etc)
Strong problem-solving and debugging skills.
Proficient with version control systems (Git)
Good knowledge of Linux-like operating systems• Knowledge of basic algorithms and data structures
Knowledge of AWS
Excellent/Fluent English level.

It Helps If You Have

Experience with front-end testing frameworks (e.g., Jasmine, Karma) and back-end testing
frameworks (e.g., Jest, Mocha).
Knowledge of cloud platforms and deployment processes (e.g., AWS, Azure).
Familiarity with agile methodologies and project management tools.
Familiarity with UI/UX design principles and accessibility standards.
Familiarity with front-end and back-end performance optimization techniques.

Why you'll love working here:

Private health insurance
Flexible work model – full remote or hybrid
Equipment of your choice (laptop, monitor, accessories)
High-growth company with innovative products
Supportive, international team
Budget for professional development (courses, books, conferences)
English and German language lessons during working hours
Nice office in Belgrade with a stocked kitchen and game area
Opportunity to learn, grow, and make a real impact

If you are looking for an environment where you can grow professionally, learn from the best in the field, balance work and life habits and have a pleasant and enthusiastic environment, please submit your CV in English.

Senior Backend PHP (Symfony) Developer - Function 365 team