Most people think a trading bot is its entry signal. It isn't. The signal is maybe 10% of what keeps an account alive. The other 90% is architecture — the boring, unglamorous plumbing that decides whether a modest edge compounds or a good idea blows up in week one.
A real trading system is five separate concerns, each replaceable without breaking the others: data feed (clean, gap-free candles or ticks), strategy engine (turns data into signals), risk layer (position sizing, max drawdown, kill-switch), execution (order placement, slippage handling, retries), and monitoring (does it still do what you tested?). Skip any one and the others can't save you.
Two traders with the identical signal get opposite outcomes based on the layers around it. One models fees and sizes positions to survive a losing streak; the other doesn't and is gone in a month. The edge lives in the harness, not the indicator everyone obsesses over.
The reason to build your own with Claude Code instead of renting a black box: you own every layer, you can read it line by line, model your own costs, and swap one piece without rewriting everything. Architecture you can read is architecture you can trust.
Build & own a transparent bot, layer by layer →