Middle/Senior Backend Engineer

ABOUT US

Xsolla is a global commerce company with robust tools and services to help developers solve the inherent challenges of the video game industry. From indie to AAA, companies partner with Xsolla to help them fund, distribute, market, and monetize their games. Grounded in the belief in the future of video games, Xsolla is resolute in the mission to bring opportunities together, and continually make new resources available to creators. Headquartered and incorporated in Los Angeles, California, Xsolla operates as the merchant of record and has helped over 1,500+ game developers to reach more players and grow their businesses around the world. With more paths to profits and ways to win, developers have all the things needed to enjoy the game.

For more information, visitxsolla.com.

ABOUT YOU

We are looking for aMiddle/Senior Backend Engineer who ispassionate about building secure, high-load identity systems to join ourXsolla ID team. The best candidate will be someone who thrives in a fast-paced, highly collaborative, and exceptionally dynamic setting and is excited todevelop a next-generation IAM (Identity and Access Management) platform that serves as the foundation for all Xsolla B2C products.

Strongbackend development skills in Go are essential, along with experience inbuilding scalable distributed systems and working with authentication/authorization protocols. The ability todesign and optimize high-availability services handling millions of users will be key to your success in this role.

If you're passionate aboutcreating reliable, secure identity solutions and loveworking on strategic platforms that directly impact user experience across gaming ecosystem, we would love to hear from you!

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 (idiomatic code, concurrency patterns, performance profiling)

  • Databases: PostgreSQL (schema design, query optimization, migrations at scale), MySQL, Redis

  • Distributed SQL: CockroachDB (multi-region deployments, clock skew handling, survivability trade-offs) for geo-distributed data residency

  • Message Streaming: NATS, Kafka (event-driven patterns, consumer groups, at-least-once delivery), RabbitMQ

  • Infrastructure: Docker, Kubernetes, Nginx

  • Identity Stack: Ory ecosystem (Hydra for OAuth2/OIDC, Kratos for identity management) with a custom Auth API orchestrator and plugin architecture

  • Protocols: OAuth 2.0 / OIDC (authorization code + PKCE, client credentials, device flow, token introspection, refresh strategies), WebAuthn

  • Web Security: cookie security, CSRF, XSS protection, secure token storage, TLS, secure session management

  • Architecture: Microservices, High Availability design

  Key Technical Challenges:

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

    • Implementing custom auth methods without forking Ory

    • SSO without third-party cookies

    • Zero-downtime migration from legacy Xsolla Login with bidirectional identity sync

    • Geo-distributed data residency via CockroachDB

    • 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 OAuth 2.0 / OIDC flows (authorization code + PKCE, client credentials, device flow), token introspection, and refresh strategies

  • Work with the Ory ecosystem (Hydra, Kratos) and extend the custom Auth API orchestrator and plugin architecture

  • Apply web security fundamentals: cookie security, CSRF/XSS protection, secure token storage, TLS, secure session management

  • Optimize database queries and ensure high performance under heavy loads (PostgreSQL, MySQL, Redis, CockroachDB)

  • Build and maintain microservices architecture with focus on reliability and scalability

  • Contribute to zero-downtime migration from legacy Xsolla Login with bidirectional identity sync

  • 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

  QUALIFICATIONS

  Required:

  • • 2+ years of commercial experience withGo

    • Strong understanding ofPostgreSQL andRedis (query optimization, indexing strategies)

    • Working knowledge ofOAuth 2.0 / OIDC auth flows (authorization code, client credentials) or strong motivation to learn

    • Understanding ofweb security fundamentals: CSRF, XSS, cookie security, TLS

    • Experience withDocker anddocker-compose

    • Proficiency withGit and collaborative development workflows

    • Understanding ofNginx and web server configuration

    • Solid experience writingunit tests and maintaining high code quality

    • Good English reading skills (technical documentation)

    Preferred:

    • • Understanding ofmicroservices architecture anddistributed systems trade-offs (consistency, availability, failure modes)

      • Experience withREST API design and documentation (Swagger/OpenAPI)

      • Hands-on experience withCI/CD pipelines

      • Familiarity with theOry ecosystem (Hydra, Kratos, Keto) or similar identity management frameworks

      • Knowledge ofPKCE, client credentials, device flow, token introspection, and refresh-token strategies

      • Experience withCockroachDB or other distributed SQL databases (multi-region deployments, clock skew handling)

      • Experience withNATS,Kafka, orRabbitMQ for event-driven / message-streaming patterns

      • Familiarity withJira for project management

      • Understanding ofKubernetes and container orchestration

      • Familiarity with compliance requirements relevant to IAM:SOC 2,ISO 27001, GDPR data minimization, audit logging

      • Practical, up-to-date experience with modern AI tools (e.g. Claude, Copilot, Cursor) for code generation, review, and accelerating day-to-day engineering work

BENEFITS

We are passionate about fostering a supportive environment for our team, so we prioritize the physical, mental, and emotional well-being of our employees through a comprehensive Benefits Program. This includes:

• Unlimited Flexible Time Off for work-life balance

• Private health insurance (ДМС) with dental coverage for you and your family

• Personalized career roadmap with clear growth paths (IC track or Leadership track)

• Professional development through training and educational opportunities

• Annual corporate events and team gatherings

• Remote-first culture with flexible working hours (10:00–19:00)

• Working at the cutting edge of the rapidly growing gaming and Web3 industry

• Knowledge sharing culture with experienced engineers across the organization

Together, we're not just building a business; we're cultivating a community that values creativity, collaboration, and the transformative power of play.