Timon F.

Full-Stack Developer

Recelia • Meio período

Apr 2025 - Present • 1 yr 7 mos

Recelia is a multi-tenant SaaS that acts as an AI receptionist for service businesses. It answers customer enquiries via web chat and WhatsApp, books appointments, answers questions about services and sends confirmations and reminders, in Croatian, German, English and Italian. I built it together with three colleagues as a full-stack developer; since founding Percelia I contribute part-time. Key parts of the platform: - Multi-tenant architecture from day one: every business is an isolated tenant, enforced at database level with PostgreSQL row-level security in an EU region - A channel-agnostic conversation engine with tool calls for booking, conflict checks and guardrails; web chat and WhatsApp plug in as adapters, and the LLM provider can be swapped - WhatsApp integration directly via Meta's Cloud API, without an intermediary provider - Escalation to a human whenever the AI is unsure, rather than risking a wrong booking - An evaluation harness of 72 real-world conversation cases that guards the AI's behaviour - A tenant dashboard with calendar, AI settings, knowledge base and test chat, plus a drag-and-drop table plan for restaurants Stack: TypeScript, Next.js, Tailwind, shadcn/ui, PostgreSQL (Supabase, Frankfurt), OpenAI API, Meta WhatsApp Cloud API, Resend, Sentry, Vercel; voice pipeline in Python with Pipecat, Telnyx and Docker containers on Fly.

Founder, Web Developer and Accessibility Specialist

Percelia

Mar 2025 - Present • 1 yr 8 mos

I run Percelia, a small web studio that builds, fixes and looks after websites and online shops so they are fast, get found and work for everyone. - Accessibility remediation under WCAG 2.2 and the European Accessibility Act, fixed in the real code (Shopify, WooCommerce, WordPress, React, Next.js) - Speed optimization, measured with Google PageSpeed before and after - Technical SEO and readability for AI crawlers - Making AI built sites (Lovable, Bolt, v0) launch ready - Built my own accessibility testing software that checks pages in a real browser on six layers Public before/after examples: PageSpeed 36 to 98, 29 automated accessibility findings to 0 on a checkout, 0 to 101 words readable without JavaScript.

Software Developer

Knoll

Apr 2024 - Dec 2025 • 1 yr 8 mos

At Knoll Feinmechanik I programmed the PLC controls of special-purpose machines that assemble and test parts for medical devices, including setup and commissioning on the machine itself. At Knoll Feinmechanik (ASD) I was part of the development team behind the company's platform for battery storage systems. I joined the project while it was already under way, got familiar with the existing codebase and development environment, and worked on how the platform handles the data the storage units produce. My contributions: - Collecting the measurement data reported by the storage units and organising it in structured tables - Evaluating the data and turning it into figures that are meaningful to customers - Preparing the results so that buyers can read the state of their system clearly on a mobile phone - Working on the platform's admin area, which the team uses to manage systems and customers - Working within the shared development environment alongside the rest of the team The work sat where hardware data meets the end customer: raw readings from physical devices had to become information a non-technical buyer understands at a glance. That experience carries over directly to projects with sensor or measurement data, dashboards, customer portals and internal admin tools.