Senior Full Stack Developer (Java + React)

Company Description

Are you a Senior Full Stack Developer who thrives on building scalable, high-performance systems? Join us at Sigma Software and contribute to a cutting-edge platform for a leading pet products marketplace — a solution designed to serve millions of customers and transform the way pet owners shop online.

In this role, you will be part of a skilled, collaborative team working with modern technologies to create a robust, customer-focused product that stands out in the e-commerce space.

Why join us? You’ll be working on a high-impact project where your ideas and technical decisions will directly influence product success and user experience.

CUSTOMER

Our Customer is an industry-leading marketplace specializing in pet products, boasting an extensive online presence and a massive product catalog.

PROJECT

The project focuses on the development and optimization of a cutting-edge, high-performance marketplace platform designed to transform the online shopping experience. You will join the team, which develops and maintains core systems for managing catalogs, pricing, and inventory. This team ensures accurate tracking of items and services (like drugs, suppliers, and tests) as well as current and incoming stock, building scalable, large-scale distributed systems that handle substantial data volumes with low latency and robust fault tolerance.

Key Technologies: Java, React, REST APIs, Distributed Systems, Event-Driven Architecture, HBase, Cassandra, MongoDB, Redshift, AWS, Google Cloud, Azure

Job Description

• Design, develop, and implement large-scale distributed systems to handle substantial data volumes, ensuring scalability, low latency, and fault tolerance
• Implement APIs and event-driven solutions to meet system requirements and enhance functionality
• Create and execute comprehensive unit tests, API tests, regression tests, and performance tests to ensure the reliability and efficiency of the system
• Utilize modern frontend frameworks like React for web development
• Optimize solutions for scalability, reliability, and high performance
• Collaborate closely with cross-functional teams to promptly address and resolve production incidents, ensuring minimal downtime and swift recovery

Qualifications

• 5+ years of experience in software development with object‑oriented programming languages, specifically Java
• Solid hands-on experience with frontend frameworks, specifically React
• Extensive experience in building multi‑tier web applications and creating REST APIs
• Strong understanding of OOP principles, design patterns, algorithms, and data structures
• Practical knowledge of cloud platforms like AWS, Google Cloud, or Azure
• Experience with CI/CD pipelines and containerization tools like Docker or Kubernetes
• Familiarity with both relational and NoSQL databases such as HBase, Cassandra, MongoDB, Redshift
• Hands‑on experience in Linux/Unix environments
• Strong analytical and problem-solving skills
• At least an Upper-Intermediate level of English

WILL BE A PLUS

• Experience with GraphQL
• Understanding of high-load system optimizations in the E-commerce domain

Additional Information

PERSONAL PROFILE

• Excellent communication skills and the ability to work with cross-functional teams
• Strong collaborative mindset and proactive approach to task ownership