// notes on tech
One public front door that quietly routes each request to the right app behind it, handles the HTTPS, and spreads the load. That front door is a reverse proxy — and you've been using one all along.
2026-07-04 · 5 min read
Three things people constantly mix up, because they all end up as 'a string in a header.' But they answer different questions — who's calling, on whose behalf, and how the server checks.
2026-07-03 · 6 min read
Your trading history is just one particular shuffle of a deck of trades. Monte Carlo asks: what do the other 9,999 shuffles look like — and was your story lucky, unlucky, or typical?
2026-07-02 · 6 min read
You wanted to buy at 100.00. You got 100.08. That gap — slippage — is quietly deducted from every trade, and most backtests pretend it doesn't exist.
2026-07-02 · 5 min read
Two strategies can finish the year up the same amount — yet one is far better than the other. The Sharpe ratio is how you tell them apart: return per unit of risk.
2026-07-01 · 5 min read
An LLM doesn't read words — it reads tokens, and it can only hold so many at once. That single limit explains why long chats 'forget' and why prompts get cut off.
2026-06-30 · 5 min read
A language model doesn't look things up — it predicts the next most-likely word. When it doesn't know, the most likely words still form a confident, fluent, and completely made-up answer.
2026-06-29 · 6 min read
When you give a language model a tool, you aren't letting it run code on your machine. You're handing it a menu and the ability to point at an item. Here's what actually happens.
2026-06-27 · 5 min read
A query that scans a million rows and one that finds the same row instantly can differ by a single line: CREATE INDEX. Here's the intuition for why.
2026-06-26 · 6 min read
APIs push back when you ask too fast. The reliable answer isn't to hammer harder — it's to wait, and to wait smarter each time.
2026-06-24 · 5 min read
That little padlock isn't decoration. Behind it is a quick negotiation — the TLS handshake — that proves who you're talking to and locks the conversation so no one in between can read it.
2026-06-23 · 6 min read
An AI model is smart but locked in a room with no hands. MCP is the standard set of doors that lets it safely reach out and use real tools. Here's the whole idea, with a picture that moves.
2026-06-20 · 6 min read
Two ways to find out when something happened: keep asking, or get told. One wastes everyone's time; the other just needs a doorbell.
2026-06-17 · 5 min read
A queue is easy when one worker reads it. It gets interesting when ten workers share the load and none of them step on each other. That's the problem Redis Streams solves.
2026-06-13 · 6 min read
The volume-weighted average price is the benchmark big traders quietly measure themselves against — a fair 'average price' that respects where the volume actually happened.
2026-06-11 · 5 min read
Give a strategy enough freedom and it will 'predict' the past perfectly — and tell you nothing about the future. That gap is where most trading ideas quietly die.
2026-06-06 · 6 min read
Delta, Gamma, Theta, Vega. They sound mystical, but each just answers one question: how much does the option's price move when one thing changes?
2026-05-30 · 5 min read
A single train/test split can just get lucky. Walk-forward slides the window forward through time, so a strategy has to prove itself again and again.
2026-05-27 · 5 min read