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