Staff Software Engineer Smart Wallet & Account Abstraction

About Xsolla

Xsolla is a global commerce company with robust tools and services to help developers solve the inherent challenges of the video game industry. From indie to AAA, companies partner with Xsolla to help them fund, distribute, market, and monetize their games. Grounded in the belief in the future of video games, Xsolla is resolute in the mission to bring opportunities together, and continually make new resources available to creators. Headquartered and incorporated in Los Angeles, California, Xsolla operates as the merchant of record and has helped over 1,500+ game developers to reach more players and grow their businesses around the world. With more paths to profits and ways to win, developers have all the things needed to enjoy the game.

For more information, visit xsolla.com.

About the Role

We are hiring a Staff Software Engineer to own the smart wallet and account abstraction layer of Xsolla ZK, Xsolla's Web3 platform on a zkSync-based L2. This is an individual contributor role with a large technical scope. You are the technical anchor for how millions of players get an on-chain account they never have to think about.

The product. Every player who signs in with Xsolla ID receives a deterministic, non-custodial smart account. The account is derived from their identity claim, is identical on every device, and its private keys never leave the client. It is not a separate wallet screen: it is the player's inventory. It backs:

• minting and gifting;
• trading on our Bazaar marketplace;
• Merkle-based reward airdrops;
• gas sponsorship;
• an in-app dApp browser that exposes the same signer to third-party applications through an EIP-1193 provider.

Responsibilities

• The technical strategy and architecture of the smart wallet platform: account model, signing, session management and gas abstraction at scale
• The smart account and permissioning model, evolved to meet both product and compliance needs
• The security model where our signer meets third-party applications: what a player is actually approving, and proof that the UI shows it
• The custody and recovery roadmap, from today's interim mechanisms (including raw key export) to MPC-based custody
• Cross-team technical decisions on account architecture, SDK contracts, data modeling and platform reliability, with buy-in from the wallet, marketplace, SDK, mobile and security teams
• Engineering standards in the Web3 domain
• Production escalations in the wallet and account abstraction domain

WHAT YOU WILL DO

• Design and evolve the ERC-4337 user operation lifecycle (prepare → sign → submit → confirm), EIP-7702 delegation, deterministic address derivation from identity, and the session-key and permission primitives (including origin-bound Smart Sessions) 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
• Define EIP-1193 / EIP-6963 provider behavior, origin-bound and policy-versioned sessions, trust tiers, and the transaction and signature confirmation flow
• Design recovery paths (passkeys, guardians, social recovery) that a non-crypto-native player can complete without losing assets
• Identify systemic risks (key management, signature phishing, reorgs and indexer staleness, bundler and RPC dependencies, contract upgrade paths) and lead initiatives that resolve them before they become incidents
• Write RFCs and design docs; review critical code, contracts and designs
• Work with product, security, legal and infra teams to align on the roadmap and turn business and regulatory needs into well-scoped technical plans
• Create leverage for the engineering org through documentation, tooling and mentorship
• Serve as the escalation point for complex production issues: a stuck user operation, a drained paymaster, a signing prompt a player didn't understand
• Set up and maintain AI tooling in the repositories (Claude Code, Codex, Cursor: rules, context, harness) so the team uses it effectively

REQUIRED

Experience

• 8+ years of engineering in the Ethereum ecosystem working with crypto wallets and smart wallets
• Designing or operating a production smart wallet or account abstraction system serving real users and real value
• Shipping and operating systems where a bug meant lost funds. You can talk concretely about the guardrails, reviews and rollback paths you put in place

Account abstraction and smart wallets

• ERC-4337 in depth: 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, signature validation for undeployed accounts (ERC-6492)
• EIP-7702 and the post-Pectra landscape: EOA delegation, its interaction with EntryPoint v0.8, and the risks it introduces (residual key authority, delegation phishing, storage collisions)
• Building on or extending production smart account implementations; modular account standards (ERC-7579 / ERC-6900)
• Session keys and delegated permissions: scoped, time-limited, policy-bound authority; TTLs and contract allowlists, origin binding, permission revocation; ERC-7710 / ERC-7715
• Signature schemes and wallet interfaces: EIP-712 typed data, ERC-1271 contract signatures, WebAuthn / passkey (P-256) signers; EIP-1193, EIP-6963, EIP-5792 batched calls, ERC-7677 paymaster interfaces

Smart contracts and EVM

• Solidity and the EVM: reading, reviewing and writing account, paymaster and module contracts; gas-aware design; upgradeability and migration patterns; working effectively with external auditors
• L2 specifics and their effect on wallet design: native account abstraction on zkSync-family chains, transaction and fee models, finality and reorg behavior, RPC and indexer semantics

Backend

• Go: idiomatic code, concurrency patterns, performance profiling
• TypeScript and SDK design: client-side SDK surfaces that internal and external teams build on
• Distributed systems and their trade-offs (consistency, availability, failure modes); reconciling off-chain state against an authoritative on-chain result

Data and infrastructure

• PostgreSQL: schema design, query optimization, migrations at scale
• Kubernetes: deploying, operating and debugging services
• Asynchronous messaging and event-driven design (Kafka or NATS): consumer groups, at-least-once delivery
• Git, CI/CD

Security

• Key management in production: platform secure storage (Keychain / Keystore), HSMs, MPC or threshold signing, and the operational discipline around each
• Wallet threat modeling: signature and delegation phishing, malicious dApp origins, replay and cross-chain replay, token approval abuse, paymaster griefing and DoS

Leadership

• Leading multi-quarter technical initiatives across teams
• Influencing architecture and standards beyond your immediate team
• RFCs and design docs that stand on their own and are actionable without you in the room

AI-assisted engineering

• Daily hands-on use of AI coding tools (Claude Code, Codex, Cursor) for development and review, including configuring them for a repository

English

• English at C1 level

Nice to Have

• Hands-on experience with ZK Stack and zk-rollups
• Hands-on experience with embedded and ecosystem wallet and AA infrastructure technologies (thirdweb, Privy, Dynamic, Turnkey, Pimlico, Alchemy, Biconomy, ZeroDev, Safe{Core}), with clear views on build versus buy
• MPC / threshold custody, social recovery or guardian-based recovery in a consumer product
• 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 authoring or reviewing ERC / EIP standards
• Compliance requirements for crypto consumer products: KYC / AML, geofencing, MiCA, SOC 2, ISO 27001, GDPR data minimization, audit logging
• Identity and auth integration for wallet derivation: OAuth 2.0 / OIDC, JWT verification, token scoping
• Platform or infrastructure engineering: building systems other engineers build on
• Owning a mobile wallet surface: React Native / Expo, WebView provider injection, native signing UI
• Gaming industry experience: platforms for game developers, publishers or players

How We Work

• Decisions in writing. Significant technical decisions are written up as an RFC or ADR that lays out the options and trade-offs. We work across time zones, so a design has to stand on its own.
• AI is part of everyday engineering. We use AI coding tools for development and review, and we treat configuring them for a codebase as real engineering work.

HOW WE HIRE

• Intro call. Your background, your motivation and the role.
• Technical interview. Built directly on the What you will own and Required sections above. We won't ask about anything this posting doesn't promise.
• System design. You design part of a wallet or account abstraction platform end to end and walk us through the trade-offs.
• Bar raiser. An engineer from outside the hiring team checks that you raise the overall engineering bar.

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 and their families through a comprehensive Benefits Program. This includes medical, dental, and vision, PTO, and a personalized career roadmap for each employee. By investing in professional development through training and educational opportunities, we ensure that our team thrives both personally and professionally. 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
• Employment Type: Full-time
• Schedule: 10:00–19:00 (flexible)