Team Lead

### 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 [](https://xsolla.com/ ""). ### ABOUT YOU We are looking for a **Team Lead** who is **passionate about building and leading teams that create cutting-edge blockchain infrastructure** to join our **Xsolla ZK team**. The best candidate will be someone who thrives in a fast-paced, highly collaborative, and exceptionally dynamic setting and is excited to **lead a team of backend engineers developing Web3 products while maintaining hands-on technical contribution**. Strong **backend development expertise in Go combined with leadership skills** are essential, along with experience in **building high-load distributed systems and managing engineering teams**. The ability to **balance technical excellence with people development and delivery predictability** will be key to your success in this role. If you're passionate about **growing engineering talent while shipping world-class blockchain products** and love **shaping the technical direction of next-generation gaming infrastructure**, we would love to hear from you! ### 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 Team Lead, you'll lead a team working on: - **Xsolla Bazaar** — NFT marketplace backend for trading digital assets across multiple blockchains - **Web3 Backpack** — Smart wallet backend with ZK SSO 4337 account abstraction - **Blockchain Services** — Event scanners, transaction processors, indexers - **Web3 APIs** — Developer-facing APIs and SDKs for game integration **Tech Stack:** - **Language:** Go (go-ethereum, ethkit; idiomatic concurrency, performance profiling) - **Databases:** MongoDB, PostgreSQL, Redis - **Message Queue:** NATS, RabbitMQ, Kafka - **API:** REST, WebSocket, gRPC, OpenAPI (Swagger) - **Account Abstraction (ERC-4337):** EntryPoint (v0.6–v0.8), UserOperation lifecycle, bundler/paymaster roles, validation rules (ERC-7562), signature validation for undeployed accounts (ERC-6492) - **Smart Account Standards:** Modular account standards (ERC-7579 / ERC-6900), session keys and delegated permissions (ERC-7710 / ERC-7715), EIP-7702 EOA delegation awareness - **Signature & Wallet-Facing Standards:** EIP-712 typed data, ERC-1271 contract signatures, WebAuthn/passkey (P-256), EIP-1193, EIP-6963, EIP-5792, ERC-7677 paymaster interfaces - **ZK Stack / ZKsync Era:** EraVM, system contracts (ContractDeployer, NonceHolder), bootloader, zksolc/zkvyper compilers, native Account Abstraction, L1↔L2 messaging and finality - **Ethereum L1:** go-ethereum, abigen, RPC and indexer semantics - **Smart Contracts:** Solidity, ERC-20/721/1155, upgradeability and migration patterns - **Custody:** Key management fundamentals (HSM, MPC/threshold signing) relevant to backend wallet operations - **Infrastructure:** Docker, Kubernetes, GitLab CI/CD, Graylog, Prometheus **Team Scope:** - Team of up to 8 backend engineers - Ownership of one or more service domains within the Web3 ecosystem - Direct collaboration with Product, Frontend, Blockchain/Solidity, and DevOps teams ### Responsibilities **Technical Leadership (60%):** - **Architect Web3 backend systems** leveraging ZK Stack infrastructure and ERC-4337 Account Abstraction primitives - Define technical strategy for the **UserOperation lifecycle**: bundler/paymaster integration, gas-sponsorship strategy (what gets sponsored, how it's metered, capped, and defended from abuse) - Lead **ZK Stack / ZKsync Era** integration decisions: EraVM-specific optimizations, native Account Abstraction, L1↔L2 bridging architecture, system contract interactions - Design **session-key and permission primitives** (ERC-7710 / ERC-7715): scoped, time-limited, contract-allowlisted authority for prompt-free gameplay transactions - Own the **signing and confirmation flow**: EIP-712 typed data, ERC-1271 verification, WebAuthn/passkey signers, and wallet-facing standards (EIP-1193, EIP-6963, EIP-5792) - Oversee **smart contract interaction layer**: abigen code generation, factory dependencies handling, upgradeability and migration patterns - Review complex code focusing on **blockchain-specific edge cases**: reorg handling, transaction finality, gas estimation failure modes on L2 - Identify systemic risks (key management, signature phishing, bundler/RPC dependencies) and lead initiatives to resolve them before they become incidents - Drive improvements in **blockchain observability**: transaction tracking, event monitoring, on-chain analytics - Maintain hands-on contribution to critical features involving multi-chain operations **People Management (40%):** - Lead and mentor a team of up to 8 backend engineers - Conduct regular 1:1s, performance reviews, and career development conversations - Hire and onboard new team members - Foster a culture of technical excellence, collaboration, and continuous learning - Manage team workload and ensure sustainable delivery pace **Delivery & Process:** - Own team's delivery predictability and sprint commitments - Collaborate with Product to refine requirements and estimate work - Report on team progress, risks, and blockers to stakeholders - Continuously improve development processes and team efficiency ### Nice to Have **Required:** *Technical Skills:* - 5+ years of commercial experience with **Go** (or 7+ years with other backend languages with Go proficiency) - Strong expertise in **distributed systems** and **microservices architecture** - Deep knowledge of **MongoDB**, **PostgreSQL**, and **Redis** - Experience with **message queues** (NATS, RabbitMQ, Kafka) - Solid understanding of **API design** (REST, WebSocket, gRPC) - Experience with **Docker**, **Kubernetes**, and CI/CD pipelines - **Blockchain development experience**: - Ethereum/EVM smart contract interaction (go-ethereum, abigen) - Understanding of transaction lifecycle, gas models, nonce management - Experience with token standards (ERC-20, ERC-721, ERC-1155) - Working knowledge of **ERC-4337 Account Abstraction**: EntryPoint, UserOperation lifecycle, bundler/paymaster roles, gas estimation failure modes *Leadership Skills:* - 2+ years of experience leading engineering teams - Track record of **mentoring and developing engineers** - Experience with **agile methodologies** and sprint planning - Strong communication skills for technical and non-technical stakeholders - Ability to balance hands-on coding with management responsibilities **Preferred:** - Experience with **ZK Stack / ZKsync Era**: - EraVM execution model and differences from EVM, native Account Abstraction on zkSync-family chains - System contracts (ContractDeployer, NonceHolder, etc.) - L1↔L2 communication, bridging, and finality/reorg behavior - Deeper **Account Abstraction & smart wallet** exposure: - Modular account standards (ERC-7579 / ERC-6900) and experience building on/extending implementations (Safe, Kernel, Biconomy, Coinbase Smart Wallet, or equivalent) - Session keys and delegated permissions (ERC-7710 / ERC-7715) - Signature schemes: EIP-712, ERC-1271, WebAuthn/passkey, and wallet-facing standards (EIP-1193, EIP-6963, EIP-5792, ERC-7677) - Familiarity with **AA infrastructure providers** (Sequence, thirdweb, Privy, Dynamic, Turnkey, Pimlico, Alchemy, ZeroDev, Safe{Core}) and views on build-versus-buy trade-offs - Exposure to **key management**: HSM, MPC/threshold signing, social recovery or guardian-based recovery - Knowledge of **smart contract development** (Solidity basics, security patterns) and wallet threat modeling (signature phishing, replay, paymaster griefing) - Experience with **blockchain event processing**: event scanning, reorg handling, webhooks - Background in **gaming** or **fintech** industries with high-load systems - Experience with **remote team management**