Xsolla - Team Lead
Requirements
• 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 • 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 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 • 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 • 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 • 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 • 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) • 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 • WHAT SUCCESS LOOKS LIKE • First 3 months: • Onboard and understand the codebase, architecture, and team dynamics • Establish regular 1:1s and team rituals • Deliver at least one significant feature or improvement • First 6 months: • Improve team's delivery predictability and code quality metrics • Identify and address technical debt in key areas • Develop career growth plans for all team members • Team consistently delivers on commitments with high quality • Measurable improvement in system performance and reliability • Team members show clear growth and development
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 • Together, we're not just building a business; we're cultivating a community that values creativity, collaboration, and the transformative power of play. • EMPLOYMENT DETAILS • Location: Remote (worldwide) • Employment Type: Full-time • Schedule: 10:00–19:00 (flexible) • Contract: Employment agreement (entity or EOR arranged per candidate location) • EQUAL EMPLOYMENT STATEMENT
Benefits
• We are passionate about fostering a supportive environment for our team, so we prioritize the physical, mental, and emotional well-being of our employees through a comprehensive Benefits Program. This includes: • Unlimited Flexible Time Off for work-life balance • Private health insurance with dental coverage for you and your family • Personalized career roadmap with clear growth paths • Professional development through training, conferences, and educational opportunities • Annual corporate events and team gatherings • Remote-first culture with flexible working hours (10:00–19:00) • Leadership development programs and coaching
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