Oleksii Trekhleb

Posted on Mar 13

I built a small app called CaliVibe to explore California counties and cities through data

#showdev #webdev #ai #opensource

Sometimes it is easier to understand a place through data rather than descriptions.

So I built a small interactive app that lets you explore California counties and cities using different metrics like:

population
crime rates
temperature trends
topographical landscape
and other geographic data

You can try it here:

👉 https://trekhleb.dev/cali-vibe/

The project is also open-sourced:

👉 https://github.com/trekhleb/cali-vibe

Demo (.gif)

What you can explore

The app lets you quickly switch between different datasets and see how regions compare.

For example you can explore:

Population distribution
Crime statistics
Temperature trends
Terrain elevation

Each dataset can reveal interesting patterns across California counties and cities.

Example views

Terrain view

Temperature trends

Crime rates per city/county

County population

County/city borders

Tech stack

The app is intentionally simple and fully client-side.

Frontend

React
TypeScript
Vite
Tailwind CSS

Visualization

MapLibre GL
Three.js

Data

JSON datasets loaded as static assets.

This means the app runs without a backend.

Data sources

Some of the data used in the project comes from:

CA DOJ OpenJustice
California Department of Finance
US Census Bureau
Open-Meteo climate datasets
Terrain tiles from AWS

The processed datasets are included in the repository.

Development experiment

Another interesting aspect of this project is that it was mostly AI-assisted development.

I vibe-coded for fun: ~98% of the code was written by Claude Code Opus with a few sprinkles from Gemini 3.1 Pro.

This made it possible to move from idea → working prototype very quickly.

Why I built this

I enjoy building small interactive tools that help explore data visually.

Sometimes a map + a few sliders can reveal patterns much faster than tables or reports.

This project was mostly a weekend experiment, but it turned into a fun way to explore California through data.

Source code

If you're curious how it works internally: