Sr. Full-Stack Engineer (Python-primary), Identity, UCP & Wallets

Role# 3 Sr. Full-Stack Engineer (Python-primary), Identity, UCP & Wallets

Must have

5+ years full-stack engineering with Python as the primary backend language for production microservices (typical modern SaaS backends), plus solid working proficiency in TypeScript/Node (Node 22) for edge, wallet, and client-facing integration work; strong fundamentals.

API security fundamentals: OAuth 2.0 (Authorization Code + PKCE, client credentials), OIDC, JWT/JWS issuance and verification, JWKS rotation, replay controls (aud, jti, TTL).

Microservices architecture experience: service-to-service auth, header verification and injection defenses, rate limiting.

Reads protocol specifications precisely and delivers from acceptance criteria without supervision.

Nice to have

Has shipped an app or integration on a third-party commerce or assistant platform (Shopify, a ChatGPT/Copilot app, a marketplace) including its OAuth install flow and review/approval process; has built an MCP server in TypeScript with authentication in front of it.

Verifiable Credentials hands-on: W3C VC 2.0 data model, OID4VCI/OID4VP, SD-JWT VC; familiarity with DID methods (did:web, did:key) and at least one wallet SDK; BBS+ / zero-knowledge predicate tooling.

Edge/serverless development (for example, AWS CloudFront Functions/View email address on us.fitly.work or equivalent) with a key-value or durable-object-style store; reads protocol specs precisely (UCP, RFC 9421, RFC 8693, OpenID specs) and cites the section.

Google UCP or Merchant Center integrations; loyalty-programme or promotions systems; e-commerce fraud or bot-management experience.

Deliverables you own. UCP signal schema + platform-agent reference mock UCP merchant with loyalty tiers header contract + edge verifier + middleware SDK VC issuer/wallet/verifier proof of concept fraud test suite integration guides demo beats.