About CALEDARO

The origin story

I was juggling several projects across teams in different time zones. A calendar sync subscription fixed it — until I reviewed my expenses and realized I'd paid over $100 in 2025 just to sync lunch breaks to my work calendar. I cancelled. Now my colleagues didn't know when I had lunch.

So I built my own. Three weekends, two weeks, and one question: what does it actually take to ship a production-ready micro-SaaS that does one thing well? That experiment became CALEDARO.

Who's behind CALEDARO

Vlad Duma — solo founder, developer, and the person who answers support emails. A developer turned Solutions Architect with 8+ years building and supporting commerce systems. AWS Certified Solutions Architect and Microsoft Azure Fundamentals certified.

Originally from Ukraine, now based in Lisbon, Portugal. The legal entity (DUMA DIGITAL SOLUTIONS S.R.L.) is registered in Romania.

How CALEDARO is built

CALEDARO isn't a wrapper around someone else's API. It's built from scratch:

• Real-time sync via Google Calendar push notifications and Microsoft Graph change notifications — events sync in ~4.3 seconds, not minutes
• Privacy by default — synced events appear as "Busy" blocks, never exposing titles, descriptions, or attendees
• EU-hosted on Hetzner servers in Germany — your data stays in the EU under GDPR protection
• AES-256-GCM encryption for all OAuth tokens at rest
• Clean exit — delete a sync and optionally remove every event it created

The tech stack is Next.js, PostgreSQL, Redis, and a standalone worker process for background sync. No serverless magic. No vendor lock-in. Just a server doing one job reliably.

Why "free forever" for 2 calendars

Because syncing two calendars shouldn't cost $100/year. That's the whole thesis. Two calendars, two accounts, no credit card, no trial expiration. If your needs are simple, you never pay. Paid plans (from €4.69/month) exist for people with more calendars and accounts — they fund the infrastructure, and the pricing is transparent and locked.

Values

Do one thing well. CALEDARO syncs calendars. It doesn't do scheduling, habits, task management, or AI productivity coaching.

Privacy is non-negotiable. Your employer doesn't need to know about your therapy appointment. Your work calendar shows "Busy" — that's it.

Transparent infrastructure. You know where your data lives (Germany), how it's encrypted (AES-256-GCM), and what permissions we use (OAuth 2.0, calendar scope only).

No lock-in. Delete your account and everything goes with it. Delete a sync and we clean up the events.

Can I contact the founder directly? Yes — email Contact us. It goes directly to Vlad, typically answered within 24 hours.