Team Lead

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

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

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