How to Backtest Your Trading Strategy Before Going Live: A Developer's Guide

(And why I lost $2,400 before learning this the hard way)

Every trading bot developer faces this moment: you've built your strategy, the backtests look gorgeous, and you're ready to print money. Then live trading starts — and your account bleeds.

I've been there. In January, my grid trading bot on Binance lost $2,400 in three days. The backtest showed 340% APY. Something was very wrong.

The culprit? I trusted backtests without questioning the data, the execution, or the market conditions. Here's how to avoid my mistakes.

The Problem with Backtests

A backtest is a simulation of your strategy on historical data. It tells you what would have happened if you'd run the bot yesterday. The issue is: past performance ≠ future results .

Here's why:

Slippage : In backtests, you buy at the exact price you see.…