Marcel Havel

Project: Multi-tenant Verification & Trust Platform

Owned end-to-end architecture and key technical decisions across security, infrastructure, and system design.

Designed and delivered production-grade platforms, including a tender management system and a sovereign AI gateway.

Built and operated own products, covering architecture, development, and infrastructure.

Defined end-to-end system architecture (backend, frontend, infrastructure) with a strong focus on security, scalability, and maintainability.

Designed and implemented OAuth2 / OIDC authentication with Keycloak, including PKCE for SPA clients.

Leveraged AI-native development workflows (Claude Code, LLMs) to accelerate architectural prototyping, perform deep-dive security audits of authentication flows, and maintain high delivery velocity in a complex multi-tenant environment.

Designed role-based authorization for multiple actor types.

Designed and implemented secure email, phone, and bank account verification workflows with rate limiting, login guards, and fraud-prevention mechanisms.

Integrated Open Banking bank account verification (TrueLayer) to strengthen trust signals during onboarding.

Designed and implemented payment and subscription workflows using Stripe, supporting secure billing, webhooks processing, and environment separation.

Designed and implemented push notification workflows for user verification and system events.

Integrated multi-cloud services:

Azure Blob Storage / Storage Accounts for secure document storage

AWS SES and AWS End User Messaging (SMS) for email and phone verification

Google Routes API for address and routing validation

Designed and implemented Infrastructure as Code, containerization, and secure secrets management.

Designed and implemented CI/CD pipelines for automated build, testing, and deployment across environments (DEV / PROD).

Focused on security-first design, fault tolerance, and long-term maintainability.