Tevaxia

Tevaxia was founded in 2025 in Luxembourg to fill a specific gap: the country's real estate market has its own rules — 5% rent cap, Bëllegen Akt, 3% VAT on hotel accommodation, commune-level energy aids — that off-the-shelf FR/BE/DE software doesn't handle correctly. We started with TEGOVA EVS 2025 valuation, then expanded to energy performance (EPBD), syndic (co-ownership), hotel PMS, and e-invoicing (EN 16931, mandatory in France from September 2026). 40+ tools today, 5 languages, all built on open European standards and exposed via a REST API.

Frontend: Next.js 16 (App Router), TypeScript strict, Tailwind CSS, next-intl (5 languages, hreflang on 200+ URLs). Backend: Supabase (Postgres + RLS + auth) on AWS EU Frankfurt, Vercel Edge. PDF: pdf-lib for PDF/A-3 Factur-X embedding, @react-pdf/renderer for TEGOVA EVS 2025 reports. Integrations: Enable Banking (PSD2 AIS), Stripe, STATEC, Observatoire de l'Habitat, Geoportail.lu, ECB Data Warehouse, PVGIS. Testing: Vitest unit + Playwright E2E. Observability: Sentry + PostHog. Source: github.com/Tevaxia · @tevaxialu/propcalc on npm.