# Krister Viirsaar
- Software developer since 2014.
- Teaching beginners programming since 2016.
- Building businesses.
## What I'm up to now
- Viru Keskus business intelligence
- Teaching at Polütehnikum
- [Tinkr.tech](https://tinkr.tech) - learn programming by building projects
- [Kirbs.ee](https://kirbs.ee) - sell your kids' clothes, hands-free
- Building a quality oriented AI sales agent for SMEs
- [3D printing & design](https://www.thingiverse.com/kristerv/designs)
## Contact
- [Book a video call](https://koalendar.com/e/meet-with-krister-viirsaar)
- [LinkedIn](https://www.linkedin.com/in/kristerv/)
- [KristerV on Discord](https://discord.com/users/kristerv)
## Past projects
- [random forest OÜ](https://randomforest.ee/) - Founder of a software development agency.
- Toitla - "Uber for catering" startup from 2016. Had clients all over Tallinn from multiple banks to small startups.
- SavvyBooks - Platform to safely track your crypto to pay taxes in the US.
## Blog
**Top 5 posts by popularity**
1. [Mailgun + DigitalOcean DNS Settings](http://code.krister.ee/mailgun-digitalocean/)
1. [Lock screen config in SwayWM](https://code.krister.ee/lock-screen-in-sway/)
1. [PostgreSQL slow with million row aggregation (how to debug)](https://code.krister.ee/postgresql-slow-with-million-row-aggregation-how-to-debug/)
1. [Stream video to browser the easy way (static HLS files)](https://code.krister.ee/stream-video-to-browser-the-easy-way/)
1. [Node.js encode/decode hex and publishing data to the bitcoin blockchain](https://code.krister.ee/node-js-encode-decode-hex-and-publishing-data-to-the-bitcoin-blockchain/)