Senior Software Engineer

About us:

Mozzart
, the largest gambling operator in Southeast Europe, has been responsibly building its business for over two decades. We started operating in 2001, with headquarters in Belgrade, and have expanded our business to 8 markets. With over 1,200 betting shops and more than 5,500 employees, we are the absolute regional leader in this industry. We are dedicated to the development and nurturing of expertise among our employees, while also caring about career advancement. We constantly improve our business and services, keeping up with technological advancements and fostering innovation. Through socially responsible work and employee care, we have carefully built a reputation as the most desirable employer.

For our
HQ in Belgrade, IT department
, we are searching for:

Senior Software Engineer (FRONTEND)

As a Frontend Engineer in Mozzart, you will be responsible for designing and developing modern, user-friendly interfaces that power millions of interactions daily. You'll work on building responsive and scalable web applications using JavaScript frameworks, ensuring smooth navigation, fast performance, and engaging user experiences. Collaborating closely with backend, product, and design teams, you'll translate complex requirements into intuitive solutions, implement new features, and maintain high standards of code quality. Additionally, you'll focus on optimizing performance, accessibility, and cross-platform compatibility to deliver a seamless experience across devices.

Your role will not be just to implement requirements, but to act as a
partner to our product team
– using your technical expertise and ideas to actively
shape the future of our digital products
and the overall user experience.

Key Responsibilities:

• Designs and implements complex, user-facing web applications using JavaScript, (or similar frameworks), HTML5, and CSS3
• Optimizes and improves existing interfaces for performance, scalability, and maintainability
• Develops and maintains modular, reusable frontend components and libraries
• Works on application architecture and participates in technology and framework selection for the frontend stack
• Participates in requirements analysis and translates business needs into intuitive UI/UX solutions
• Writes unit and integration tests using tools like Jest, Mocha, or Cypress to ensure code quality
• Collaborates with backend, design, and DevOps teams to enable seamless integrations and efficient CI/CD pipelines
• Provides mentorship and support to less experienced frontend developers
• Follows industry trends and introduces innovations in JavaScript, frontend frameworks, and UI/UX best practices
• Troubleshoots UI/UX issues and performs root cause analysis of frontend-related errors
• Active involvement throughout the entire product lifecycle – from initial idea and technical analysis, through design, to implementation and success measurement.
• Close collaboration with UX/UI designers to identify the best technical solutions for delivering an outstanding user experience, while providing constructive feedback on design.
• Proactively suggesting website improvements, whether related to performance, new features, technical debt, or enhancements to the development process.

Requirements:

• Minimum 7 years of professional experience in software development, with a strong focus on JavaScript and modern frontend frameworks (e.g., , React)
• Hands-on experience in designing and developing complex, user-facing web applications
• Strong knowledge of JavaScript (ES6+), HTML5, and CSS3, with a solid understanding of component-based architecture
• Experience working with state management libraries (e.g., Vuex, Redux, or Pinia)
• Familiarity with version control tools, especially Git
• Experience working with build and dependency management tools like Webpack, Vite, or npm/yarn
• Practical experience in writing unit and integration tests using tools such as Jest, Mocha, Jasmine, or Cypress
• Familiarity with CI/CD tools and processes (e.g., GitLab CI, Jenkins, or GitHub Actions)
• Understanding of RESTful APIs, WebSockets, and integration with microservice-based backends
• Knowledge of frontend design patterns, refactoring techniques, performance optimization, and best coding practices
• User-oriented mindset and a passion for creating products that solve real problems, not just "check off" tasks.
• Proactive and analytical approach to problem-solving, with a drive to always understand the "why" behind each task

Candidates with the following will have an advantage:

• Experience in performance optimization for high-traffic websites.
• Advanced knowledge of TypeScript.
• Hands-on experience with CI/CD tools (e.g., GitLab CI, Jenkins).
• Familiarity with architectural patterns such as micro-frontends.
• Experience in developing and maintaining design systems.
• Experience working on products that integrate AI/ML functionalities.

Your work-life balance is essential to us, so we offer you:

• days of annual leave
• 38 working week, because we value your time
• Flexible working hours
• Hybrid working model

Your health and well-being is crucial to us, so we have you covered:

• Private health insurance
• Annual health check up
• Mental health and well-being initiatives
• Open feedback culture

We care about your personal development and professional growth, so we provided:

• Career development program
• Opportunity to take technical, language and soft skills trainings

If you are interested in the mentioned position and meet the required qualifications, please submit your CV through the application process.

We appreciate every candidate who applies for the position, and we will contact those candidates with whom the selection process will be initiated.