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