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

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

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