Software Engineer - Wallets
Remote · Worldwide
Rain is the global stablecoin payments platform for enterprises, neobanks, platforms, developers, and AI agents. Rain's infrastructure allows partners to move, store, and use stablecoins instantly and compliantly through global payment cards, rewards, on/off-ramps, wallets, and cross-border rails.
As both a Visa and Mastercard Principal Member, Rain issues cards accepted at more than 175 million merchant locations across 220+ countries and territories. Trusted by over 100 organizations worldwide and backed by top-tier investors including ICONIQ, Sapphire Ventures, Dragonfly, Bessemer Venture Partners, and Lightspeed, Rain recently completed a $250M Series C valuation at $1.95B.
Role Summary
Rain is looking for exceptional engineers to build the next generation of wallet infrastructure from the ground up, supporting both custodial and non-custodial architectures. Instead of merely integrating off-the-shelf SDKs, you will tackle foundational engineering challenges across cryptography, distributed key generation, secure computing, and transaction signing pipelines capable of securing high-value customer assets.
Key Responsibilities
Wallet Architecture: Own the end-to-end design of Rain’s wallet infrastructure, engineering resilient systems for custody, key management, transaction signing, authorization, and recovery.
Cryptographic & Signing Systems: Design flexible signing infrastructure integrating MPC, HSMs, secure enclaves, and TEEs without introducing operational fragmentation.
Account Models & Standards: Build and evolve wallet systems across diverse account models—including EOAs, smart contract wallets, account abstraction (ERC-4337), embedded wallets, and cross-chain setups.
Key Management Lifecycle: Architect security-critical key management processes covering generation, distributed key generation (DKG), secure storage, rotation, backups, and hardware isolation.
Security & Policy Controls: Set the technical standard for wallet security, encompassing threat modeling, policy engines, programmable authorization, secrets management, and recovery protocols.
Strategic Build vs. Buy: Evaluate and make foundational build-versus-buy architectural decisions across cryptography and custody primitives.
Requirements & Qualifications
Must-Haves
Senior Systems Engineering: Extensive background building, hardening, and operating mission-critical distributed systems and backend infrastructure.
Wallet & Cryptography Depth: Deep domain knowledge in wallet security, cryptographic primitives, signing protocols (MPC, multi-sig), or secure enclaves/HSMs.
Production Reliability: Proven track record building high-throughput, fault-tolerant infrastructure handling high-value digital asset transactions.
Standards Familiarity: Thorough understanding of Ethereum/EVM account models, transaction mechanics, and modern wallet standards (e.g., ERC-4337).
Autonomy & First-Principles Thinking: High-agency engineer capable of architecting new infrastructure standards from scratch in an open, flat environment.
Compensation & Benefits
Annual Base Salary: $220,000 – $270,000 USD
Equity: Competitive equity grant
Bonus: Performance-based bonus structure
Work Model: 100% Remote