# Ramon Raniere

> Software engineer. A technical knowledge base laid out as a filesystem:
> every path is a topic, every leaf is one idea written down once.

Every page has a plain-markdown twin at <url>index.md.

## Site

- [Ramon Raniere - Software Engineer](https://ramonraniere.com/): Technical knowledge base organized as filesystem.
- [projects](https://ramonraniere.com/projects/): an erp that 500+ cellphone shops run on, a crypto payment api, and an seo engine. all three built and shipped solo.
- [resume](https://ramonraniere.com/resume/): full-stack software engineer in brasília, brazil. 6+ years building saas products end to end: multi-tenant erp, crypto payment infrastructure, rest apis.
- [Full corpus](https://ramonraniere.com/llms-full.txt): every page above and every note below, as plain text.

## databases

query planning, indexing, and the trade-offs behind them. most of what looks like a slow database is a plan you did not read.

- [GiST index](https://ramonraniere.com/knowledge/databases/postgresql/postgis/gist-index/): stores bounding boxes, not shapes. every spatial query is therefore two phases, and the slow ones are slow in the second phase, not the first.
- [ST_Contains](https://ramonraniere.com/knowledge/databases/postgresql/postgis/st-contains/): true when b is entirely inside a and their interiors overlap. that second clause is the surprise: a point sitting exactly on the border is not contained.
- [ST_DWithin](https://ramonraniere.com/knowledge/databases/postgresql/postgis/st-dwithin/): answers "is b within n units of a" and, unlike ST_Distance, it can reach a spatial index. that single difference is why it is almost always the right proxi…

## frontend

good design is a feast for the eyes and good usability keeps the door open

- [useRef](https://ramonraniere.com/knowledge/frontend/react/hooks/useref/): one box that survives every render and never causes one. the other half of useState: change it and the screen does not notice.
- [useState](https://ramonraniere.com/knowledge/frontend/react/hooks/usestate/): a value react remembers between renders. the catch is that it is a snapshot of the render that read it, not a variable you update in place.
- [token storage](https://ramonraniere.com/knowledge/frontend/security/token-storage/): there is no safe place to keep a token in the browser. the question is not where you put it, it is how much an attacker gets when they reach it.
- [reactivity](https://ramonraniere.com/knowledge/frontend/vue/reactivity/): vue watches the value, react re-runs the function. almost every difference between the two frameworks falls out of that one decision.