Benjamin W.-Senior Fullstack Engineer (TypeScript): SaaS and AI integration

Building an open-source CRM with AI integrations

Open-source CRM for small teams, offered as a cloud version and as a self-hosted core product. I own the product technically end-to-end: user interface, business logic, data model, interfaces and operations. Since December 2025, I have been working full-time on Customermates.

Responsibilities:

• Designed and built the CRM workflows for contacts, organizations, deals and tasks, with configurable table and board views.
• Frontend with Next.js, React, Tailwind CSS and MobX; backend business logic with Node.js, Prisma and PostgreSQL, input validation with Zod.
• Built a REST API, webhooks and an MCP interface that lets external applications and AI clients work directly with the CRM.
• Integrated AI assistant based on the Vercel AI SDK, with stored conversations and streamed responses.
• Developed and maintain an n8n community integration for CRM operations and event-driven automations.
• Build, delivery and operations with Docker, GitHub Actions and Vercel, both as a cloud offering and for self-hosting.

Results:

• Product live as a cloud and self-hosted version; source code and integrations public on GitHub.
• More than 200 GitHub stars for the CRM repository (as of 09/2026).

Frontend: TypeScript, React, Next.js, Tailwind CSS, MobX

Backend and data: Node.js, Prisma, PostgreSQL, Zod

APIs and AI: REST, Webhooks, MCP, Vercel AI SDK, n8n

Cloud and CI/CD: Docker, GitHub Actions, Vercel

Rebuilding the frontend of a fintech platform

Angular-based fintech web application.

Responsibilities:

• Led the complete frontend rebuild over two years, from architecture principles to implementation.
• Built and maintained a design system of components, UI patterns and development guidelines, documented in Storybook and visually tested with Chromatic.
• Established frontend principles and test automation: unit tests with Jasmine, architecture tests with TSArch, golden-file tests.
• Migrated from Bootstrap to Tailwind CSS and introduced Redux for state management.
• Took part in the initial backend migration from Java to Kotlin.

Results:

Development velocity increased by (23%).

• Shared components and guidelines as a common foundation for frontend development across the team.

Frontend: Angular, TypeScript, Tailwind CSS, Redux, Bootstrap (legacy)

Testing and quality: Storybook, Chromatic, Jasmine, TSArch, Golden-file tests

Backend: Java, Kotlin, PostgreSQL

Cloud environment: GCP, Kubernetes, Helm, Terraform

Taking an HR product from concept to MVP

HR product MVP with a Flutter frontend and a TypeScript / NestJS backend, run serverless on GCP and validated together with pilot customers.

Responsibilities:

• Defined the MVP scope and led the entire fullstack implementation.
• Developed the Flutter frontend and the TypeScript / NestJS backend with Prisma.
• Cost-efficient serverless deployment with GCP Cloud Functions and Firebase, automated via GitLab CI/CD.
• Built a network of pilot customers, psychologists, HR leaders and investors.

Results:

• MVP completed; three companies onboarded as beta customers.

Frontend: Flutter

Backend and data: TypeScript, NestJS, Prisma

Cloud and CI/CD: GCP Cloud Functions, Firebase, GitLab CI/CD

Building an enterprise document management system

Fullstack enterprise application for managing and analyzing documents under GDPR requirements, with a React frontend and a Node.js / PostgreSQL backend.

Responsibilities:

• Dual role combining product ownership with fullstack development of the document management system.
• Developed the React / TypeScript frontend and the Node.js / PostgreSQL backend.
• Frontend quality assurance with Storybook and Jest; deployment with Docker and Netlify.
• Worked with clean code, SOLID principles and design patterns in Scrum and Kanban processes.
• Exposure to SAP backend administration.

Frontend: TypeScript, React, Storybook, Jest

Backend and data: Node.js, PostgreSQL

Cloud and delivery: Docker, Netlify

Methods: Scrum, Kanban, Clean Code, SOLID