Senior Node.js Developer

⭐️ CoreStar is a dynamic technology company supporting partners in heavy-load industries with high-performance solutions. Our expert teams bring a startup-driven mindset, focusing on innovation, collaboration, and efficiency in every project. At CoreStar, you’ll have the opportunity to grow your skills, tackle exciting challenges, and directly contribute to impactful products.

📌 Key Responsibilities:

Develop scalable backend systems - design and implement high-load applications capable of handling massive traffic with optimal performance

Build robust APIs and microservices - create RESTful services, GraphQL APIs, and real-time WebSocket connections for complex distributed systems

Optimize application performance - identify bottlenecks, implement caching strategies, and ensure optimal resource utilization in production environments

Design and implement third-party integrations - connect external APIs, payment systems, and various service providers while maintaining system reliability

Develop from concept to production - participate in the full development lifecycle, from initial architecture design through deployment and monitoring

📌 Technical Excellence

Ensure code quality and maintainability - write clean, well-documented code following best practices and design patterns

Monitor and troubleshoot production systems - investigate complex issues, optimize database queries, and maintain system stability

Collaborate with cross-functional teams - work closely with product managers, designers, and other developers to deliver high-quality solutions

Stay current with technology trends - continuously learn and evaluate new tools, frameworks, and best practices in the Node.js ecosystem

📌  Requirements:

5+ years of professional software development experience with a strong focus on backend systems

4+ years of hands-on Node.js development in production environments with deep understanding of JavaScript runtime internals

3+ years of experience with high-load systems - building applications that serve large user bases with high availability requirements

Proven track record of performance optimization - experience with scaling applications, database optimization, and system architecture

📌
Technical Skills

Advanced JavaScript and TypeScript proficiency - ES6+, async/await, promises, and TypeScript for large-scale applications

Node.js ecosystem mastery - Express.js, Fastify, or similar frameworks with deep understanding of event loop and performance optimization

API development expertise - RESTful services, GraphQL implementation, WebSocket connections, and third-party API integrations

Database optimization - MySQL, MongoDB, Redis with advanced query optimization, indexing strategies, and schema design

Message queuing and streaming - Apache Kafka or NATS for building distributed, event-driven architectures

Monitoring and observability - Prometheus, Grafana, ELK stack for comprehensive system monitoring and debugging

Containerization and orchestration - Docker for development and deployment, Kubernetes for production scaling

Cloud platform proficiency - AWS or Azure services with experience in auto-scaling, load balancing, and distributed systems

📌 Additional Qualifications 

Strong English communication skills - ability to participate in technical discussions and document complex systems

Performance-focused mindset - deep understanding of scalability principles, caching strategies, and optimization techniques

Problem-solving expertise - capacity to debug complex distributed systems and design elegant solutions for challenging technical problems

📌 Benefits:
🏝 24 working days of paid annual leave 
🤝 6 days of paid sick leave  
🖊 Official employment
📄 Medical insurance
☕️ Coffee zone with fruit & snacks available in the office 
🥗 Corporate Lunch provided by the company
💪 Gym and sports classes 
🙌 Healthy and friendly work atmosphere  
📚 Greek and English language classes (partially covered)

Join us and be one of the Core Stars! ⭐