Web3 Fullstack Engineer

Location: Serbia Workplace: remote About You We’re looking for a Web3 Fullstack Engineer to build the layer where web2 and web3 meet. Our mission is seamless web2 ↔ web3 integration — letting players and developers interact with digital items and move them through their full lifecycle (mint, own, trade, transfer, redeem, retire) without ever having to think about which side of the chain they’re on. You’ll work across the whole stack: wallet-connected frontends, high-throughput backend services, and the smart contract and indexing layers that make on-chain items feel as fast and familiar as anything in web2. This is a hands-on engineering role with broad ownership. A player buying an item with a credit card, a game granting an in-game asset, and a marketplace settling a peer-to-peer trade should all resolve to the same coherent item model — regardless of whether the item lives in a database, a custodial wallet, or on-chain. Making that experience invisible to the end user, and reliable for the developer, is the core of the job. You care about product quality and developer experience as much as protocol correctness. You’re comfortable owning a feature end to end, reasoning about trust and custody boundaries, and making pragmatic calls about what belongs on-chain versus off-chain.   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, visit xsolla.com Responsibilities Build Seamless Web2 ↔ Web3 Integration — Design and ship the flows that let users move between traditional accounts/payments and on-chain wallets without friction: custodial and non-custodial wallets, account abstraction, gasless transactions, and fiat on-ramps. Own the Digital Item Lifecycle — Build the systems behind item mint, ownership, transfer, trading, and redemption — keeping on-chain state and off-chain records consistent, auditable, and fast. Develop Fullstack Features — Deliver end to end across wallet-connected frontends, backend services, and the smart contract / indexing layer that powers item ownership and turnover. Model Items & Ownership — Design data models and APIs that represent items uniformly whether they live off-chain, in a custodial wallet, or on-chain, and keep them in sync. Ensure Reliability of Value Flows — Anything that moves items or money must be correct under failure: idempotency, reconciliation, replay safety, and clear recovery paths. Integrate Blockchains & Marketplaces — Interact with EVM chains, token standards, indexers, and marketplace/settlement flows; abstract their differences behind clean internal interfaces. Collaborate Across Teams — Work with product, security, payments, and game-facing teams to turn business needs into well-scoped technical plans, and document decisions so they stand on their own. What You Bring Web3 & Digital Assets Web2 ↔ Web3 Integration — Hands-on experience bridging traditional systems with on-chain ones: wallet onboarding, custodial vs. non-custodial trade-offs, account abstraction, gasless/relayed transactions. EVM & Smart Contracts — Working knowledge of EVM chains and Solidity, including reading, integrating with, and reasoning about the safety of contracts. Token & Item Standards — Practical understanding of ERC-20, ERC-721, and ERC-1155, and how they map to real game items, ownership, and transfers. On-chain / Off-chain Sync — Experience keeping blockchain state consistent with off-chain databases: indexing, event ingestion, reorg handling, and reconciliation. Frontend Engineering TypeScript & React — Strong TypeScript and React skills for building responsive, production-grade interfaces. Wallet Integration — Experience with wallet connectivity and web3 client libraries (e.g. wagmi, viem, ethers.js, WalletConnect) and embedded/social login wallets. Backend Engineering Backend Services — Solid backend skills in Node.js and Go: clean APIs, concurrency, and performance under load. Distributed Systems — Experience with distributed systems and their trade-offs (consistency, availability, failure modes), especially where correctness of value transfer matters. Data & Infrastructure PostgreSQL — Schema design, query optimization, and migrations at scale. Kubernetes — Deploying, operating, and debugging services in a k8s environment. Message Streaming — Kafka or NATS — event-driven patterns, consumer groups, at-least-once delivery. Git & CI/CD — Git and modern CI/CD practices. Domain Context Gaming Industry Experience — Experience building or operating platforms for game developers, publishers, or players — especially anything touching in-game items, economies, or ownership. Nice to Have Experience building NFT marketplaces, item trading, or secondary-market / settlement systems Familiarity with blockchain indexing tooling (The Graph, custom indexers) and node/RPC infrastructure Experience with account abstraction (ERC-4337), smart wallets, or paymaster/relayer setups Background in payments or fiat on-ramp integration bridging traditional commerce and crypto Experience with non-EVM ecosystems (Solana, etc.) or cross-chain / bridging patterns Familiarity with security and compliance relevant to digital assets: custody, key management, audit logging, KYC/AML touchpoints Contributions to open-source web3, wallet, or tooling projects Hands-on, 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 and a personalized career roadmap for each employee. By investing in professional development through training and educational opportunities, we ensure that our team thrives both personally and professionally. Together, we’re not just building a business; we’re cultivating a community that values creativity, collaboration, and the transformative power of play.   The duties and responsibilities of this position may evolve over time to support the organization’s goals and individual growth. This job description is intended to outline the general nature and level of work being performed and is not intended to be an exhaustive list of all duties, responsibilities, and qualifications required.   By submitting your application, you consent to Xsolla conducting background checks, where permitted by law, after the final interview stage. All checks will comply with local regulations, and your information will be handled confidentially.   Xsolla takes your privacy seriously and will not sell or externally distribute any personal data received during the hiring process. In accordance with applicable data protection laws, Xsolla is committed to protecting your personal information and respecting your privacy.   For any inquiries related to data privacy, please contact: careers@xsolla.com   Explore more opportunities at: https://xsolla.com/careers