I'm Building an App That Connects You with Strangers from Anywhere in the World

#dotnet #buildinpublic #flutter #sideprojects

The Idea

Most people will never visit most places on Earth.
But everyone can have a conversation.

That thought sparked Meridian – an app that connects you with random people from any country, in any language. Think Omegle meets Duolingo meets a digital passport.

How It Works

Pick a place – Tap anywhere on the map
Get matched – Connect with someone who actually lives there
Chat in any language – Real-time translation handles the rest
Collect stamps – Build your digital passport with every conversation

The Tech Stack

I just shipped the waitlist landing page and wanted to share the stack:

Backend API

.NET 8 Minimal APIs
PostgreSQL on Render
Entity Framework Core for data access

Frontend

Vanilla HTML/CSS/JS (no framework needed for a landing page)
CSS custom properties for theming
Intersection Observer for scroll animations

Infrastructure

Render for hosting (API + static site + database)
Auto-deploy from GitHub

Some Code Highlights

Spam Protection
Instead of adding reCAPTCHA (which hurts UX), I implemented invisible protection:

// Honeypot field - bots fill it, humans don't see it
if (!string.IsNullOrEmpty(request.Website))
{
    Console.WriteLine($"🤖 Bot detected: {ipAddress}");
    // Return fake success to not tip off the bot
    return Results.Ok(new WaitlistResponse(true, "Success", 999));
}
// Rate limiting - 3 signups per IP per hour
if (rateLimiter.IsRateLimited(ipAddress))
{
    return Results.BadRequest(new WaitlistResponse(false, "Too many requests"));
}

UTM Tracking
To see which platforms drive signups, I capture the source from the URL:

const urlParams = new URLSearchParams(window.location.search);
const utmSource = urlParams.get('utm_source') || 'landing-page';
// Later, in the fetch request:
body: JSON.stringify({
    email: email,
    source: utmSource
})

Now I can share links like mysite.com?utm_source=devto and track conversions by platform.

Lessons Learned

Render's free tier works great for MVPs, but the cold start (50+ seconds) is rough
Proxy IPs are tricky – I had to use X-Forwarded-For header for rate limiting
Honeypot fields are surprisingly effective against basic bots
Vanilla CSS with custom properties is all you need for a polished landing page

What's Next