Software Engineer - Wallets

As a principal member of Visa and Mastercard, Rain issues cards accepted at more than 175 million merchant locations across over 220 countries and territories. The company serves more than 100 organizations worldwide.

In January 2026, Rain closed a $250 million Series C funding round led by ICONIQ, reaching a valuation of $1.95 billion.

About the Role

Rain is looking for an experienced Wallet Infrastructure Engineer to architect and build its next generation of wallet infrastructure, spanning custodial and non-custodial systems.

You'll tackle foundational challenges in cryptography, key management, secure computing and blockchain infrastructure. You'll help shape the architecture of systems responsible for securing high-value assets, with the freedom to make critical technical decisions and define the future of wallet infrastructure.

This role is suited to engineers with deep expertise in wallet security, cryptography or custody infrastructure and the ability to lead complex architectural projects.

What You'll Do

• Own the architecture of Rain's wallet infrastructure, designing secure and scalable systems for custody, key management, transaction signing, authorization and recovery.
• Design flexible signing infrastructure supporting MPC, HSMs, secure enclaves, TEEs and emerging cryptographic approaches.
• Build and evolve wallet systems across EOAs, smart contract wallets, account abstraction, ERC-4337, embedded wallets and multichain infrastructure.
• Define the architecture connecting cryptography, wallet orchestration, keys, signing authority, transaction policies and authorization.
• Design security-critical key management systems, including key generation, distributed key generation, storage, rotation, backup and recovery.
• Build highly available signing and transaction infrastructure for securing high-value customer assets while maintaining reliable, developer-friendly APIs.
• Set the technical direction for wallet security, including threat modeling, policy engines, secrets management, authentication and programmable authorization.
• Make strategic build-versus-buy decisions across cryptography, custody, wallet and security infrastructure.

What We're Looking For

• Deep expertise in wallet infrastructure, custody, cryptography or security infrastructure, combined with strong distributed systems and architectural fundamentals.
• Experience designing or building production wallet, custody, signing or key management systems, particularly those securing high-value assets.
• Strong knowledge of applied cryptography, including MPC, threshold cryptography, threshold signatures, distributed key generation, ECDSA, EdDSA or secure multiparty computation.
• Experience with HSMs, secure enclaves, TEEs, confidential computing or hardware-backed key isolation.
• Strong understanding of blockchain account architecture, including EOAs, smart contract wallets, account abstraction, ERC-4337, transaction orchestration and multichain systems.
• Experience designing authentication, authorization, policy, permissions, recovery or secrets-management systems where security and correctness are critical.
• A proven track record of making architectural decisions in complex distributed systems, balancing security, reliability, developer experience and extensibility.
• Ability to communicate technical trade-offs, lead architectural initiatives and take ownership from initial design through production.

Benefits and Perks

• Unlimited paid time off: Flexible vacation policy, with a minimum of 10 days off per year.
• Flexible working: Work remotely, from an office or a combination of both, with a home-office setup stipend.
• Health benefits: For US employees, 95% coverage of health, dental and vision plans, including 90% coverage for dependents.
• Retirement plan: 401(k) with a 4% company match for eligible US employees.
• Equity: Stock options for all employees.
• Health and wellness: Monthly stipend for eligible fitness and wellness expenses.
• In-office meals: Lunch and dinner covered through DoorDash credits for employees working from the office.
• Team summits: Domestic and international company and team offsites.