Staff Software Engineer Smart Wallet & Account Abstraction

As a Staff Software Engineer for Smart Wallet and Account Abstraction at Xsolla, you own the technical strategy and architecture of how millions of players get an on-chain account they never have to think about. You join a Web3 platform built on zkSync, where every player who signs in with Xsolla ID receives a deterministic, non-custodial smart account derived from their identity, identical on every device, with private keys that never leave the client. This is an individual contributor role with outsized technical scope: you set direction, make hard architectural calls, and raise the bar across the organization.

What you'll do

• Own the technical strategy and architecture of the smart wallet platform, covering the account model, signing, session management, and gas abstraction at scale.
• Design and evolve the ERC-4337 user operation lifecycle (prepare, sign, submit, confirm), EIP-7702 delegation, deterministic address derivation from identity, and session-key and permission primitives that let players act without a prompt on every transaction.
• Set the paymaster and gas-sponsorship strategy: what you sponsor, how you meter and cap it, how you defend it from abuse, and how it degrades when sponsorship is unavailable.
• Own the security model where the signer meets third-party applications: EIP-1193 and EIP-6963 provider behavior, origin-bound and policy-versioned sessions, trust tiers, and the transaction and signature confirmation flow. Define what a player is actually approving and make sure the UI can prove it.
• Lead the custody roadmap from 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 cross-team technical 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 (key management, signature phishing, reorgs and indexer staleness, bundler and RPC dependencies, 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 infrastructure 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 EIP-7702, EOA delegation, 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 and 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 and ERC-7715).
• Practical command of EIP-712 typed data, ERC-1271 contract signatures, WebAuthn and passkey (P-256) signers, and wallet-facing standards: EIP-1193, EIP-6963, EIP-5792 batched calls, and 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 (for example, Coinbase, Kraken, Base, Safe, the Ethereum Foundation, Consensys, or MetaMask), or a comparable wallet, exchange, or account-abstraction infrastructure team where wallet correctness and custody were core to the product.
• Track record of shipping and operating systems where a bug meant lost funds, with concrete knowledge of the guardrails, reviews, and rollback paths you put in place.
• Ability to read, review, and write account, paymaster, and module contracts; gas-aware design; upgradeability and migration patterns; and 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, internal and external, 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 expertise: schema design, query optimization, migrations at scale.
• Experience deploying, operating, and debugging services in a Kubernetes environment.
• Experience with message streaming (Kafka or NATS): event-driven patterns, consumer groups, at-least-once delivery.
• Proficiency with Git and modern CI/CD practices.
• Hands-on experience with key material in production: platform secure storage (Keychain and 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 documents 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 and 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}), with clear views on where to build versus buy.
• Experience with MPC and threshold custody, social recovery, or guardian-based recovery in a consumer product.
• Experience with NFT and token infrastructure at scale: ERC-721, ERC-1155, and 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 and EIP standards.
• Familiarity with compliance requirements relevant to crypto consumer products: KYC and AML, geofencing, MiCA, SOC 2, ISO 27001, GDPR data minimization, audit logging.
• Experience with identity and authentication 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 (for example, Claude, Copilot, Cursor) for code generation, review, and accelerating day-to-day engineering work.

About Xsolla

Xsolla is a global commerce company providing robust tools and services to help developers solve challenges in the video game industry. Headquartered in Los Angeles, Xsolla operates as the merchant of record and has helped over 1,500 game developers reach more players and grow their businesses worldwide. From indie to AAA studios, companies partner with Xsolla to fund, distribute, market, and monetize their games.