I built a small web toy for a very demanding client: a toddler named Daniel who is obsessed with trucks.
You can play with it here: truck.hearter.io
Source code: github.com/barlevalon/daniel-truck-animation
It's a simple semi-truck driving down a scrolling road. But the process of building it was the real fun part. Instead of coding in isolation, we turned it into a collaborative game.
Iterating with AI
What made this possible was how fast we could move using AI tools. In the past, if a child asked "can it honk?", you'd have to say "give me 20 minutes to find an audio clip and write the code." By the time you were done, they'd have moved on to something else.
With modern coding agents, the loop is almost instantaneous. When he wanted it to be night time, one prompt later the sky turned dark and stars appeared. When he asked for headlights, boom, beams of light cutting through the dark.
The Ultimate Product Designers
Kids make for incredible product managers. They have zero tolerance for latency or bad UI, and they know exactly what they want. "Make it honk!" "More wheels!" "It needs to bounce!"
By treating him as the primary customer and letting him drive the design decisions, the computer became a magic wand rather than just a screen. We weren't just programming, we were building a toy together in real-time.
The final result is a simple HTML/JS page with no frameworks or build steps. Just pure, instant fun. But the memory of building it together is the real feature.