Team Lead

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