Shipping fast as a solo founder means you will introduce security bugs. That's not a question of skill — it's a question of bandwidth. The question is whether you catch them before someone else does. I'm building Pronto — an open-source self-hosted POS, CRM, and booking system for service businesses. During a security review of v1.0, I found three issues that made me genuinely uncomfortable. None were exploited. All are now fixed. Here's what they were, why they happened, and how I fixed each one. Bug 1: Bot tokens leaking to client-side HTML What happened Pronto supports Telegram, WhatsApp, and Viber notifications. Each tenant configures their own bot credentials in Settings. These credentials are stored in the database and used server-side to dispatch notifications. In an early version, I had a notification preview endpoint that fetched tenant settings — including bot tokens — and returned them in a JSON response that was consumed directly by a client-side component.…