Senior Backend Developer (Java)

Project Overview 

You will be joining a mature, data-driven digital health platform that helps users better understand their health, performance, and longevity through personalized insights. The product aggregates and processes large volumes of biometric, laboratory, and lifestyle data, transforming them into actionable recommendations using advanced analytics. 

From a technical perspective, this is a high-load, production-grade system with: 

• complex backend logic and data pipelines, 
• heavy API usage and third-party integrations, 
• strict requirements for reliability, performance, and scalability, 
• continuous growth in users, data volume, and feature set. 

The platform operates as a long-running SaaS product with a strong focus on backend architecture, data consistency, and system evolution rather than short-term feature delivery. 

Responsibilities 

• As a Senior Backend Developer, you will: 
• Design, develop, and maintain backend services written in Java 
• Participate in architecture design and contribute to long-term technical decisions 
• Build and evolve RESTful APIs used by web and mobile clients 
• Develop and support microservices in a distributed environment 
• Work with relational and NoSQL databases, optimizing queries and data models 
• Design scalable solutions for high-load and data-intensive workloads 
• Integrate third-party services and internal platform components 
• Ensure code quality through clean, maintainable, and well-tested code 
• Participate in code reviews, technical discussions, and system design sessions 
• Collaborate with frontend, QA, DevOps, and product teams 
• Contribute to performance optimization, reliability improvements, and technical debt reduction 

Requirements 

Must-have 

• 7+ years of professional backend development experience 
• Strong knowledge of Java (11 or higher) 
• Excellent understanding of OOP, design patterns, and clean architecture principles 
• Strong experience with Spring / Spring Boot and modern Java ecosystem 
• Solid experience with RESTful architecture and API design 
• Experience building and operating microservices 
• Experience with AWS or other cloud platforms (AWS preferred) 
• Experience with MySQL and/or PostgreSQL 
• Experience with NoSQL databases (e.g., MongoDB, DynamoDB, Redis) 
• Experience with Git and Jira 
• Understanding of backend scalability, performance tuning, and distributed systems 
• Familiarity with Docker, container-based deployment, and Linux environments 
• Experience working with high-load or data-intensive systems 
• Ability to write clean, readable, and maintainable code 
• English level: B2 (Upper-Intermediate) or higher 

Nice to have 

• Experience with message brokers (RabbitMQ, Kafka, or similar) 
• Experience with CI/CD tools (TeamCity, Jenkins, GitHub Actions, etc.) 
• Experience with Kubernetes or container orchestration 
• Experience working in Agile/Scrum environments 
• Knowledge of build tools (Maven or Gradle) 
• Basic knowledge of GNU/Linux and bash