Web3 Cryptography Jobs

About the Company

Rain is the global stablecoin payments platform for enterprises, neobanks, platforms, developers, and AI agents. Our technology allows partners to move, store, and use stablecoins instantly and compliantly through global payment cards, rewards, on/offramps, wallets, and cross-border rails. As both a Visa and Mastercard Principal Member, Rain issues cards that work at more than 175 million merchant locations in over 220 countries and territories. Built natively for stablecoins and trusted by more than 100 organizations worldwide, Rain delivers secure, scalable infrastructure that makes money move freely and instantly around the world.

You will have the opportunity to deliver massive impact at a hypergrowth company backed by some of the top investors in fintech, crypto, and SaaS. In January 2026, we closed a $250M Series C led by ICONIQ, valuing Rain at $1.95B, with Sapphire Ventures, Dragonfly, Bessemer Venture Partners, Galaxy Ventures, FirstMark, Lightspeed, Norwest, and Endeavor Catalyst also participating. If you're curious, bold, and excited to help shape a borderless financial future, we'd love to talk.

Our Ethos

We believe in an open and flat structure. You will be able to grow into the role that most aligns with your goals. Our team members at all levels have the freedom to explore ideas and impact the roadmap and vision of our company.

About the Team

We’re building the next generation of wallet infrastructure at Rain, supporting both custodial and non-custodial architectures. Our team is tackling foundational problems across cryptography, key management, secure computing, and blockchain wallet infrastructure—not simply integrating existing wallet SDKs. We’re looking for exceptional engineering leaders and senior individual contributors who can architect these systems from the ground up, bring deep expertise in one or more areas of wallet security and infrastructure, and have the technical breadth to work across multiple wallet architectures. Most importantly, we want engineers who are excited to push the technical frontier and define what modern wallet infrastructure should look like, rather than reproduce the standard stack that exists today.

What You'll Do

• Own the architecture of Rain’s wallet infrastructure, designing secure, scalable systems for custody, key management, transaction signing, authorization, and recovery.

• Design flexible signing infrastructure that can support MPC, HSMs, secure enclaves, TEEs, and emerging cryptographic approaches without creating fragmented systems.

• Build and evolve wallet systems across multiple account models, including EOAs, smart contract wallets, account abstraction, ERC-4337, embedded wallets, and multichain infrastructure.

• Define the boundaries between cryptography and wallet orchestration, including how keys, signing authority, transaction policies, permissions, and authorization interact across the platform.

• Architect security-critical key management systems covering key generation, distributed key generation, storage, rotation, backup, recovery, and hardware-backed isolation.

• Build highly available signing and transaction infrastructure capable of securely controlling high-value customer assets while maintaining reliable, developer-friendly APIs.

• Set the technical direction for wallet security, including threat modeling, policy engines, secrets management, account recovery, authentication, and programmable authorization.

• Make foundational build-vs.-buy decisions across cryptography, custody, wallet, and security infrastructure while ensuring the architecture can evolve alongside new blockchain standards and cryptographic techniques.

What We're Looking For

• Deep expertise in one or more areas of wallet, custody, cryptography, or security infrastructure, combined with strong distributed systems and architecture fundamentals.

• Experience designing or building production wallet, custody, signing, or key management systems, particularly infrastructure responsible for securing high-value assets.

• Strong knowledge of applied cryptography, such as MPC, threshold cryptography, threshold signatures, distributed key generation, ECDSA, EdDSA, or secure multiparty computation.

• Experience with HSMs, secure enclaves, TEEs, confidential computing, hardware-backed key isolation, or other security-critical infrastructure.

• Strong understanding of modern wallet and 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 track record of making high-leverage architectural decisions in complex distributed systems, including evaluating tradeoffs across security, reliability, developer experience, and extensibility.

• The ability to form strong technical opinions, communicate tradeoffs clearly, and own architecture from first principles through production, rather than simply integrating existing wallet or custody providers.

Things that enable a fulfilling, healthy and happy experience at Rain:

Unlimited time off 🌴 Unlimited vacation can be daunting, so we require Rainmakers to take 10 days minimum for themselves.

Flexible working ☕ We support a flexible workplace – work from home, come into an office, or both. We want everyone to work in an environment where they're their most confident and productive selves. New Rainmakers receive a stipend to set up a comfortable home workspace.

Easy to access benefits 🧠 For US Rainmakers, we cover 95% of your health, dental, and vision plan costs and 90% for your dependents, plus a 100% company-subsidized life insurance plan.

Retirement goals💡 Plan for the future with confidence. We offer a 401(k) with a 4% company match.

Equity plan 📦 Every Rainmaker gets an equity option plan so we all benefit from our success.

Health and Wellness 📚 High performance begins from within. Rainmakers receive a monthly stipend to be used for eligible health and wellness spending like gym memberships/fitness classes, massages, acupuncture - whatever recharges you!

In-office meals 🍜 Rainmakers working from the office enjoy lunch and dinner on us, covered with a DoorDash credit.

Team summits ✨ Summits play an important role at Rain. Time together helps us build relationships and a common destiny. Expect team and company offsites, both domestic and international.