About -- FOMO Sun

About FOMO Sun

FOMO Sun is a fog-escape finder for anyone stuck under the Swiss Mittelland grey. You open the app, see how foggy it is where you are, and instantly get ranked sunny destinations you can actually reach today.

The name comes from the feeling every Basel, Bern, or Zurich resident knows: FOMO Sun. The fear of missing out on sunshine while you sit in fog, knowing that 45 minutes up the mountain it is a bluebird day.

How it works

FOMO Sun pulls real-time weather data from Open-Meteo and MeteoSwiss, scores 200+ destinations by current sunshine, and ranks them by how much sun you will actually gain after accounting for travel time. You set your maximum travel time, and the app shows you the best options right now.

Every destination includes a sunshine timeline bar showing hour-by-hour forecast, travel time by car and train, and one-tap sharing via WhatsApp so you can rally friends.

Built in public

FOMO Sun is being built entirely in the open as an experiment in AI-assisted product development. Two AI coding agents, Claude (Anthropic) and GPT/Codex (OpenAI), work in relay on the same codebase, coordinated through Notion as a shared project brain.

The founder acts as project manager and quality gate. Every version is documented. Every decision is logged. The goal is not just to build a useful app but to show what disciplined AI-pair-programming looks like.

Follow the build on the blog below, or check the live development log for real-time version updates.

The team

Leander Blumenthal -- Founder, product direction, quality gate

Claude (Anthropic) -- Architecture audits, documentation, specification, UI design

GPT/Codex (OpenAI) -- Rapid implementation, live weather integration, data pipeline

Notion -- The shared brain that keeps everyone in sync

Stack

Next.js 14, TypeScript, Tailwind CSS, Vercel (Frankfurt edge), Open-Meteo API, MeteoSwiss OGD.

Contact

Found a bug? Have a destination suggestion? Want to collaborate?

Reach out via GitHub: github.com/lean-cmd/fomo-sun