Staff Software Engineer Smart Wallet & Account Abstraction

As a Staff Software Engineer for Smart Wallet & Account Abstraction at Xsolla, you own the technical strategy and architecture of our smart wallet platform. You are the technical anchor for how millions of players get a non-custodial, deterministic on-chain account they never have to think about. You set direction, make hard architectural calls, and raise the bar across the organization, operating with significant autonomy while building buy-in across engineering, product, security, and legal.

What you'll do

• Own the technical strategy and architecture of our smart wallet platform, covering the account model, signing, session management, and gas abstraction at scale
• Design and evolve our ERC-4337 user operation lifecycle (prepare, sign, submit, confirm), EIP-7702 delegation, deterministic address derivation from identity, and the session-key and permission primitives that let players act without a prompt on every transaction
• Set the paymaster and gas-sponsorship strategy: what we sponsor, how we meter and cap it, how we defend it from abuse, and how it degrades when sponsorship is unavailable
• Own the security model where our signer meets third-party applications: EIP-1193 / EIP-6963 provider behavior, origin-bound and policy-versioned sessions, trust tiers, and the transaction and signature confirmation flow
• Lead the custody roadmap from today's interim mechanisms toward MPC-based custody, and design recovery paths (passkeys, guardians, social recovery) that a non-crypto-native player can complete without losing assets
• Drive decisions on account architecture, SDK contracts, data modeling, and platform reliability, and build buy-in across the wallet, marketplace, SDK, mobile, and security teams
• Identify systemic risks such as key management, signature phishing, reorgs and indexer staleness, bundler and RPC dependencies, and contract upgrade paths, and lead initiatives to resolve them before they become incidents
• Define engineering standards, review critical code, contracts, and designs, and create leverage for the team through documentation, tooling, and mentorship
• Collaborate with product, security, legal, and infra teams to align on roadmap and translate business and regulatory needs into well-scoped technical plans
• Serve as the go-to escalation point for complex production issues in the wallet and account abstraction domain

What you bring

• Deep, hands-on understanding of ERC-4337: EntryPoint (v0.6 through v0.8), the UserOperation lifecycle, bundler and paymaster roles, validation rules (ERC-7562), gas estimation and its failure modes, counterfactual deployment, and signature validation for undeployed accounts (ERC-6492)
• Working knowledge of EOA delegation via EIP-7702, its interaction with ERC-4337 EntryPoint v0.8, and the trade-offs and risks it introduces (residual key authority, delegation phishing, storage collisions)
• Experience building on or extending production smart account implementations (Safe, Kernel, Biconomy, Coinbase Smart Wallet, or equivalent), and familiarity with modular account standards (ERC-7579 / ERC-6900)
• Experience designing scoped, time-limited, policy-bound authority: session keys with TTL and contract allowlists, origin binding, permission revocation, and delegated-permission standards (ERC-7710 / ERC-7715)
• Practical command of EIP-712 typed data, ERC-1271 contract signatures, WebAuthn / passkey (P-256) signers, and the wallet-facing standards: EIP-1193, EIP-6963, EIP-5792 batched calls, ERC-7677 paymaster interfaces
• Experience designing or operating a production smart wallet or account abstraction system serving real users and real value
• Substantial engineering experience at a large crypto product or protocol organization such as Coinbase, Kraken, Base, Safe, the Ethereum Foundation, Consensys / MetaMask, or a comparable wallet, exchange, or account-abstraction infrastructure team where wallet correctness and custody were core to the product
• Shipped and operated systems where a bug meant lost funds, and can talk concretely about the guardrails, reviews, and rollback paths you put in place
• Ability to read, review, and write account, paymaster, and module contracts in Solidity; gas-aware design; upgradeability and migration patterns; working effectively with external auditors
• Understanding of L2 execution differences and how they affect wallet design: native account abstraction on zkSync-family chains, transaction and fee models, finality and reorg behavior, and RPC and indexer semantics
• Strong Go (Golang) engineering skills: idiomatic code, concurrency patterns, performance profiling
• Ability to design and own client-side SDK surfaces in TypeScript that other engineering teams build on top of
• Experience with distributed systems and their trade-offs (consistency, availability, failure modes), and with reconciling off-chain state against an authoritative on-chain result
• PostgreSQL schema design, query optimization, and migrations at scale
• Experience deploying, operating, and debugging services in a Kubernetes environment
• Experience with Kafka or NATS: event-driven patterns, consumer groups, at-least-once delivery
• Hands-on experience with key material in production: platform secure storage (Keychain / Keystore), HSMs, MPC or threshold signing, and the operational discipline around each
• Solid grasp of the wallet attack surface: signature and delegation phishing, malicious dApp origins, replay and cross-chain replay, token approval abuse, and paymaster griefing and DoS
• Proven ability to lead multi-quarter technical initiatives across teams
• Track record of influencing architecture and standards beyond your immediate team
• Ability to write RFCs and design docs that people actually read

Nice to have

• Experience working in the video game industry, building or operating platforms for game developers, publishers, or players
• Hands-on experience with the zkSync / Elastic Chain ecosystem (ZKSync OS, Matter Labs stack, native AA and paymaster flows, custom L2 operations)
• Experience with embedded and ecosystem wallet providers or AA infrastructure vendors (thirdweb, Privy, Dynamic, Turnkey, Pimlico, Alchemy, Biconomy, ZeroDev, Safe{Core}) and clear views on where to build versus buy
• Experience with MPC / threshold custody, social recovery, or guardian-based recovery in a consumer product
• Experience with NFT and token infrastructure at scale: ERC-721 / ERC-1155 / ERC-20 mechanics, marketplace contracts, Merkle-based airdrop and claim distribution, chain indexing services
• Contributions to open-source wallet, security, or identity projects, including authorship or review of ERC / EIP standards
• Familiarity with compliance requirements relevant to crypto consumer products: KYC / AML, geofencing, MiCA, SOC 2, ISO 27001, GDPR data minimization, audit logging
• Experience with identity and auth integration for wallet derivation (OAuth 2.0 / OIDC, JWT verification, token scoping)
• Background in platform or infrastructure engineering, building systems other engineers build on top of
• Experience owning a mobile wallet surface (React Native / Expo, WebView provider injection, native signing UI)
• Hands-on, up-to-date experience with modern AI tools (such as Claude, Copilot, Cursor) for code generation, review, and accelerating day-to-day engineering work

About Xsolla

Xsolla is a global commerce company helping developers solve challenges in the video game industry. The company provides tools and services to help indie to AAA studios fund, distribute, market, and monetize their games, and has helped over 1,500 game developers reach more players worldwide. Xsolla is headquartered in Los Angeles, California, and operates as the merchant of record for its partners.