Software Engineer, Frontend / Full Stack (Identity Platform)

About Phantom

Phantom combines industry-leading security with thoughtfully designed tools to make powerful financial tools feel approachable and easy to use. The platform has grown to 20M+ users, reaching #1 in the Google Play Store finance category and consistently ranking as a Top 50 app across all categories.

Role Description

Identity Platform is the trust root of Phantom, owning authentication, unlocking, onboarding/key generation, and the signing pipeline that every transaction flows through. This is a business-critical area where bugs can lock users out or put funds at risk. You'll ship TypeScript across browser, Node.js, and mobile runtimes to keep these foundations fast, secure, and reliable.

Responsibilities

• Own and evolve the signing path for every transaction in Phantom
• Build and harden authentication, unlocking, biometrics, and account access flows across web and mobile
• Ship passkeys (WebAuthn) and MFA improvements with a strong security/usability balance
• Own onboarding and key lifecycle flows: key generation/derivation, seed phrase flows, seedless registration, hardware wallet pairing
• Own sensitive key export/import experiences and related safety rails
• Write and maintain high-signal, non-flaky tests (unit/integration/e2e) for critical paths; ensure safe rollouts via monitoring and staged releases

Required Qualifications

• 7+ years of experience
• Strong TypeScript skills; comfortable shipping code across browser, Node.js, and mobile JS runtimes
• Proven ability to build high-signal, low-flake test suites for critical systems
• Familiarity with auth concepts and common mechanisms (sessions/tokens, MFA/OTP, WebAuthn/passkeys)
• Strong engineering fundamentals: system design, debugging, and production reliability

Nice-to-Have Qualifications

• Deeper experience with OAuth2/OIDC, WebAuthn internals, cryptography, or key management systems
• Web3/wallet or signing-flow experience
• Security- or money-adjacent experience (identity, payments, custody)
• Rust experience or strong interest in learning it