Middle/Senior Backend Engineer

ABOUT THE PROJECT

Xsolla ID is a strategic core service - the centralized identity provider for the entire Xsolla ecosystem. It is not just a login form; it's a comprehensive IAM platform enabling authentication and authorization across all B2C products, including Xsolla Wallet, Xsolla App, Web Shops, and partner integrations.

Tech Stack:

Language: Go

Databases: CockroachDB

Infrastructure: Docker, Kubernetes, Nginx

Protocols: OAuth 2.0, OpenID Connect, WebAuthn

Architecture: Microservices, High Availability design

Key Technical Challenges:

Building Web2 & Web3 authentication flows (OTP, passkeys, biometrics, wallet-based login)

High availability and scaling for millions of concurrent users

SDK development and integration with multiple Xsolla products

RESPONSIBILITIES

• Develop and maintain backend services for the Xsolla ID platform using Go
• Design and implement authentication/authorization flows (OAuth 2.0, OIDC, WebAuthn)
• Optimize database queries and ensure high performance under heavy loads (CockroachDB, MySQL, Redis)
• Build and maintain microservices architecture with focus on reliability and scalability
• Write clean, well-tested code with comprehensive unit and integration test coverage
• Collaborate with frontend engineers on SDK and widget integration
• Participate in code reviews and contribute to technical documentation
• Support production systems and troubleshoot issues across the authentication stack

REQUIREMENTS

• Required:
• 3+ years of commercial experience with Go
• Strong understanding of PostgreSQL and Redis (query optimization, indexing strategies)
• Experience with Docker and docker-compose
• Proficiency with Git and collaborative development workflows
• Understanding of Nginx and web server configuration
• Solid experience writing unit tests and maintaining high code quality
• Good English reading skills (technical documentation)
• Preferred:
• Understanding of microservices architecture principles
• Experience with REST API design and documentation (Swagger/OpenAPI)
• Hands-on experience with CI/CD pipelines
• Familiarity with Jira for project management
• Knowledge of OAuth 2.0, OpenID Connect, or other authentication protocols
• Experience with RabbitMQ or similar message brokers
• Understanding of Kubernetes and container orchestration
• Sharing of GitHub profile is a plus