Senior Software Engineer – Identity & Agent Protocols (f/m/d)

Trusted Shops creates digital trust between people, businesses, and AI Agents. Every day, millions of consumers rely on our solutions to make confident online decisions, while businesses use our products to build trust, strengthen customer relationships, and grow sustainably.  With around 700 colleagues across Europe, more than 25,000 online shops, and over 40 million consumers in our Community of Trust, we are helping shape a safer and more transparent digital world. But trust is not only at the heart of our products – it also shapes how we work together. We believe in collaboration, ownership, and the freedom to do your best work through a flexible hybrid work culture.  Join us and help create a digital world where trust, transparency, and meaningful connections drive every interaction.    To strengthen our Engineering Team, we are looking for a  Senior Software Engineer - Identity & Agent Protocols (f/m/d) Cologne (hybrid) or Berlin (remote) | Permanent Contract (Full-time)  We're building the trust layer for agentic & human commerce: a Trust Authority that issues and verifies credentials for AI agents acting on behalf of consumers and shops. The protocol, the APIs and the UI - you would be a core engineer on it. Your Key Responsibilities as a Senior Software Engineer (f/m/d): Design and build the APIs and services behind our Trust Authority - credential issuance, verification, refresh and revocation. Develop cross‑platform Web Components Work with open identity standards such as OAuth2 / OIDC, passkeys, Verifiable Credentials, did:web, Web Bot Auth Own the system design - service boundaries, data models, API contracts - and make the calls that others build on. Build and run it on AWS with Terraform (Lambda, ECS, API Gateway, DynamoDB, KMS), including monitoring and alerting. Ingest and analyse agent traffic, and turn raw signals into something we can act on. Own our automated testing: build the end-to-end, contract and visual regression suites in CI (Playwright) from scratch, so we release without manual regression checking. Take features from unclear idea to production and keep them healthy. Strong backend engineering, ideally in Node.js / TypeScript. Depth matters more to us than the specific language - part of our stack is Java (Keycloak). Frontend experience with JavaScript, TypeScript, HTML, CSS. Real API and system design experience: you've designed APIs other teams depend on, and you can explain your trade-offs. Hands-on AWS and infrastructure as code (Terraform). You deploy your own changes. Solid security fundamentals: OAuth2 / OIDC, secure API design, and the basics of signing and key management. You've built automated test suites others rely on, not just tests alongside your own features. Hands-on with a modern E2E framework such as Playwright or Cypress. You're comfortable when the answer isn't known yet, and you decide with incomplete information. Nice-to-haves: Verifiable Credentials, DIDs,