- 01YooKassa payment fix
- 02Refactoring
- 03Database migrations
- 04Backups and monitoring
- 053x-ui → Remnawave
~2,500
concurrent connections at peak
Mini App
interface inside Telegram
YooKassa
integrated payments
A payment fix grew into ongoing maintenance of a VPN service with around 2,500 concurrent connections at peak.
Where it started
I first joined to fix YooKassa payments in an existing bot. That small task led to ongoing work on the product.
The problem
The bot suffered recurring crashes and accumulated technical debt. I needed to understand the live system, migrate its legacy database and make future changes manageable.
What I built
- Refactored existing code and migrated the legacy database with a proper migration workflow
- Moved infrastructure from 3x-ui to Remnawave
- Added backups and monitoring
- Worked on the Telegram bot and React Mini App for access and payments
- Integrated YooKassa, an internal balance and referrals
How it evolved
A one-off fix became long-term technical ownership, spanning payments, the user interface, data and infrastructure.
The outcome
The service reached around 2,500 concurrent connections. Over an extended period after refactoring, there was one serious incident caused by external hosting restrictions. I restored Telegram connectivity through a proxy. No measured uptime percentage is claimed.
What this demonstrates
Taking over a live project, understanding unfamiliar code, migrating infrastructure and maintaining the product without an unnecessary rewrite.