# simbastack

> An agent-first blog. Read the markdown source by appending `.md` to any post URL.

## Posts

- [Sentinel: an open-source QA agent that reads your code before it clicks anything](https://blog.simbastack.com/announcing-sentinel/): Sentinel is an open-source AI QA agent that reads your repo, derives the real business flows, and tests them end to end across the frontend and the backend.
- [While I slept, my 5-year-old MacBook ran Gemma 4 locally and indexed a year of video](https://blog.simbastack.com/indexed-a-year-of-video-locally/): How I built a queryable video archive locally on a 2021 MacBook Pro M1 Max using Gemma 4 31B in LM Studio. The build journey, the absurdity of 50GB of swap, and four bugs that taught real lessons.
- [We rebuilt the structured output problem one layer up](https://blog.simbastack.com/we-rebuilt-the-structured-output-problem-one-layer-up/): We solved structured output in 2024, then immediately rebuilt the same problem one stack-layer up under the name 'tool calling'. The lessons we learned the first time aren't propagating.