Senior Fullstack 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 the project

 

Xsolla ZK is building a cross-game infrastructure that empowers gamers to freely trade and use their digital assets without barriers. As a Fullstack Engineer, you'll work across the entire stack:

Products:

• • Xsolla Bazaar — NFT marketplace for trading digital assets

  • Web3 Backpack — Smart wallet with account abstraction

  • Web3 SDKs — Developer toolkits for blockchain integration

  • Admin Panels — Internal tools for managing Web3 operations

  Tech Stack:

  Backend:

  • • Language: Go (go-ethereum, ethkit)

    • Databases: MongoDB, PostgreSQL, Redis

    • API: REST, WebSocket, gRPC, OpenAPI (Swagger)

    • Message Queue: NATS, RabbitMQ, Kafka

    • Blockchain Infrastructure:

    • ZK Stack / ZKsync Era (EraVM, system contracts, native Account Abstraction)

    • Account Abstraction (ERC-4337): EntryPoint, UserOperation lifecycle, bundlers, paymasters

    • Ethereum L1 integration, abigen contract bindings

    Frontend:

    • • Languages: JavaScript (ES6+), TypeScript

      • Frameworks: React, Next.js, React Native

      • State Management: RTK, Zustand

      • Styling: Tailwind CSS, Tamagui, CSS-in-JS

      • Web3 Libraries & Standards:

      • Wallet provider standards: EIP-1193, EIP-6963 (multi-wallet discovery), EIP-5792 (batched calls)

      • ethers.js, viem for Ethereum interactions

      • wagmi for React hooks

      • WalletConnect for multi-wallet support

      • Embedded/AA wallet SDK (e.g. Sequence, thirdweb, Privy, Dynamic, or equivalent) for social-login smart accounts

      Infrastructure:

      • • DevOps: Docker, Kubernetes, GitLab CI/CD

        • Monitoring: Graylog, Prometheus

        Key Technical Challenges:

        • • Full-Stack Web3 Features: Building end-to-end flows from smart contract events to real-time UI updates

          • Account Abstraction Integration: Implementing embedded/smart-account wallets with social auth, ERC-4337 UserOperation flows, and gasless transactions via paymasters

          • ZK Stack Backend: Working with EraVM differences, native Account Abstraction on zkSync-family chains, handling L1↔L2 bridging operations

          • Signature & Session Handling: Implementing EIP-712 signing, ERC-1271 verification, and session-key-scoped permissions for in-game transactions

          • Cross-Platform Consistency: Sharing business logic between web and mobile using React/React Native

           

Responsibilities

 

Backend Development:

• • Develop backend services inGo usinggo-ethereum/ethkit for wallet operations and blockchain interactions

  • Implement and monitor theERC-4337 UserOperation lifecycle (prepare→sign→submit→confirm) against bundlers and paymasters

  • Implement smart contract interaction layer withabigen-generated Go bindings

  • BuildAccount Abstraction support: paymaster gas-sponsorship logic, session-key issuance (ERC-7710 / ERC-7715) for gameplay transactions

  • DesignBFF services orchestrating data from multiple blockchain sources, indexers, and wallet infrastructure providers

  Frontend Development:

  • • Build responsive applications usingReact/Next.js integrated with an embedded/AA wallet SDK

    • ImplementEmbedded Wallet flows: social auth (Google, Apple), email login, passkey (WebAuthn/P-256) support

    • Create Web3-enabled UIs usingwagmi hooks andviem for contract reads/writes, following EIP-1193/EIP-6963 provider standards

    • Implement transaction confirmation flows that clearly convey what the player is approving (EIP-712 typed-data signing)

    • Develop real-time features with WebSocket subscriptions for blockchain events

    • Build cross-platform components withTamagui for web and React Native

    Full-Stack Integration:

    • • Design and implement complete features fromsmart contract events to UI updates

      • HandleZK Stack specifics: EraVM gas model differences, native Account Abstraction, L1↔L2 bridging UI flows

      • Implementtransaction tracking: status polling, reorg handling, user notifications

      • Createadmin panels for managing NFT drops, marketplace settings, and analytics

      • Write comprehensive tests for both backend (Go) and frontend (Jest, React Testing Library)

      • Document APIs using OpenAPI/Swagger and maintain technical documentation

        

       

Nice to Have

 

Required:

Backend Skills:

• • 3+ years of commercial experience withGo

  • Strong knowledge ofREST API design and implementation

  • Experience withMongoDB and/orPostgreSQL

  • Understanding ofmicroservices architecture

  Frontend Skills:

  • • 3+ years of experience withReact and modern JavaScript/TypeScript

    • Proficiency instate management solutions (Redux, Zustand, etc.)

    • Experience withresponsive design and CSS frameworks

    • Understanding ofweb performance optimization

    General:

    • • Experience withGit and CI/CD pipelines

      • Familiarity withDocker and containerization

      • Strong problem-solving and communication skills

      Preferred:

      Web3 & Blockchain:

      • • Working knowledge ofERC-4337 Account Abstraction: EntryPoint, UserOperation lifecycle, bundler/paymaster roles

        • Understanding ofsession keys and delegated permissions (ERC-7710 / ERC-7715) and signature schemes (EIP-712, ERC-1271, WebAuthn/passkey)

        • Familiarity withwallet provider standards: EIP-1193, EIP-6963, EIP-5792

        • Exposure to anembedded/AA wallet SDK (Sequence, thirdweb, Privy, Dynamic, Turnkey, or equivalent):

        • Embedded Wallet integration (social auth, passkeys)

        • Indexer/data-availability integration for balance/activity tracking

        • Gas-sponsorship / transaction-relay APIs

        • Knowledge ofZK Stack / ZKsync Era:

        • Understanding of EraVM vs EVM differences

        • L1↔L2 communication patterns

        • Native Account Abstraction on zkSync-family chains

        • Experience withethers.js,viem, andwagmi for React

        • Understanding ofsmart contract interaction: ABI, events, transaction lifecycle

        • Knowledge oftoken standards (ERC-20, ERC-721, ERC-1155)

        Additional:

        • • Experience withNext.js SSR/SSG and App Router

          • Familiarity withReact Native andTamagui for cross-platform

          • Understanding ofWebSocket for real-time blockchain events

          • Knowledge ofKubernetes and cloud infrastructure

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 and their families through a comprehensive Benefits Program. This includes:

• 100% company-paid medical, dental, and vision plans

• Unlimited Flexible Time Off

• Personalized career roadmap for each employee

• Professional development through training and educational opportunities

• 401(k) retirement plan

• Equity participation opportunities

• Remote-first culture with flexible collaboration across time zones

• Working at the cutting edge of Web3, blockchain, and gaming technology

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

EQUAL EMPLOYMENT OPPORTUNITY STATEMENT

Xsolla is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We do not discriminate based on race, color, religion, sex, national origin, age, disability, sexual orientation, gender identity, or any other characteristic protected by law.

We consider qualified applicants with criminal histories in accordance with the Fair Chance Act.

Criminal History Consideration:

For this position, we will conduct a background check that may include:

• Criminal history check

• Employment verification

• Education verification

Relevance to Job Responsibilities:

The background check is relevant to this position because of the following role responsibilities:

• Handling sensitive financial information and blockchain transactions

• Accessing confidential company data and user information

• Ensuring compliance with regulatory requirements

Rights Under the Fair Chance Act:

Applicants are encouraged to inquire about their rights under the Fair Chance Act. If you have questions regarding our hiring practices, please contact careers@xsolla.com.

CONTACT

If you have questions regarding our hiring practices, please contact careers@xsolla.com.

For more vacancies, visit:xsolla.com/careers