Technical

Inside Kaiju

What made Character.ai's early models so engaging? Before open-source models became the norm, our team built Kaiju - a family of in-house LLMs designed to power millions of fast, expressive conversations every day with an eye towards safety. Our latest blog post looks back at that foundational work....

Scaling Our Logging System

At Character.AI, our infrastructure handles thousands of GPUs, powering billions of active user seconds and supporting millions of users every month. This massive scale produces a staggering amount of log data, which...