Kacho
Data engineer building side hustles in public. I write about what I ship — with the real, verified numbers behind it.Data engineer building side hustles in public. I write about what I ship — with the real, verified numbers behind it, not just the story.
Writing
I'm open-sourcing my Polymarket market making bot.
The market-making bot that made me about $5k on Polymarket is now on GitHub, MIT-licensed, wallet still public. Here's what's in it, what I stripped out, and why giving away a bot that made money costs me nothing - the code was never the edge.
Adverse selection eating away my Polymarket bot arbitrage profits.
Last post I left a question hanging - the directional bets lost $3,184 when every one was supposed to have at least 7% edge. Analytics scripts I built gave me a clear picture but there is not a single simple answer that explains why my ROI decayed. The main reason was that I was using stale odds (up to 30 minutes fresh) which resulted in adverse selection fills a lot more often than I thought would happen.
I recorded Polymarket's 5-minute crypto markets for two months. Here's the dataset.
A free, open dataset: nearly 89,000 of Polymarket's 5-minute crypto up/down markets (BTC, ETH, SOL, XRP, DOGE, HYPE, BNB), captured second by second - about 26.8 million top-of-book order-book observations from March to May 2026. I collected it to backtest a bot. You can have it.
I ran an arbitrage bot on Polymarket. Here are the real numbers.
In early 2026 my bot netted ~$5k on Polymarket. The guaranteed arbitrage made +$8.3k - but capturing it forced directional bets that lost $3.2k. The whole story, with every number.
Everyone shows the wins. I'm showing the wallet.
Why kacho.io exists: a logbook of the side hustles I'm actually building, with the real numbers behind them - the losing months included, and a public wallet so you can check.