Should I use a platform or write my own trading bot?

Write your own if the engineering is the hobby; use a platform if the trading is. A self-built bot means owning authentication and token refresh, order lifecycle and partial fills, data feeds and their gaps, error handling, hosting, monitoring, and reconciliation — a rewarding project and a part-time job. A platform amortizes all of that across users and adds what solo bots almost never have: order-level guardrails, tested broker adapters, sleeve accounting, and a backtest engine guaranteed identical to live execution. The strategy logic — the part you actually care about — is expressible either way. A reasonable path: prototype and validate on a platform in an afternoon; write custom code only when you hit a genuine limitation, not before.