Senior Ruby on Rails Engineer | SaaS | APIs | AI Agents | MCP | ERP & Data Integration | Hotwire | Architecture

11/2022 – offen

Senior Software Engineer and Development Lead for the ERP/CRM platform and the customer and supplier portals of a B2B sourcing company for industrial manufacturing parts. Responsible for architecture, implementation and operation of several Rails applications (API, CRM, identity/frontend app) on a shared PostgreSQL database, including technical leadership of the development team and establishing engineering standards.

Key areas:
• Backend architecture with Ruby on Rails 7/8, Dry.rb, PostgreSQL, Sidekiq/Solid Queue: REST API, JWT-based authentication, role- and field-level permission system (custom gem), full change history (PaperTrail).
• Modern frontend platform with Inertia.js, React 19, TypeScript, Tailwind and shadcn/ui, plus Hotwire/Turbo in the CRM: configurable saved list views, DSL-driven record pages, Kanban boards, global search, guided tours, Web Push.
• Customer and supplier portal (inquiries, quotes, orders) with OTP login, rate limiting and Content Security Policy.
• Integration and real-time data synchronization with Microsoft Dynamics 365 Business Central (incl. AL extensions), Microsoft Entra ID SSO, Microsoft Graph and SendGrid (inbound/outbound email).
• CRM features: leads, opportunities, campaigns, tasks and events, email sending with reply tracking, duplicate merging.
• Workflow automation (trigger → criteria → actions) and AI assistance features (LLM assistant, upsell intelligence, translation workshop) with cost governance following a propose-confirm-execute principle.
• Quality and delivery: several thousand automated tests (RSpec, Vitest, Playwright), coverage gates, CI/CD with GitHub Actions and CircleCI, deployment with Docker/Kamal.
• Information security: security audits, mapping of controls to code, and achieving ISO/IEC 27001 certification.

Postgresql, Microsoft Dynamics, Ruby, Typescript, Backbone.Js, React (JavaScript library), Ruby on Rails

12/2020 – 7/2022

Development and ongoing evolution of a web-based point-of-sale platform for the hospitality industry.

The system includes table and order management, product management, multiple printer workflows, kitchen displays, customer-facing screens, takeaway orders, split payments and payment-terminal integration.

Responsibilities included backend and frontend development, architecture, business logic, API integrations, database design, testing, debugging, deployment and production support.

Technologies:

Software Architecture, Software Design, Software engineering / -technik, Softwareentwickler