ProxyFlow — a rotating-proxy SaaS
A platform for rotating proxy exits across different countries — one entry point, quota-based plans, automatic replacement of unhealthy exits, and metrics for everything.
What it is
ProxyFlow is my most “product-shaped” project: a real SaaS with signups, plans and subscriptions. The customer gets one proxy address with a username and password — and behind it lives a pool of exit points across different countries. Want a fresh IP in another country? One click, and traffic flows through a new exit without touching any settings.
The engineering part
The interesting thing about such a platform isn’t the proxying — it’s keeping the pool alive. Exits are containers that are born, get sick and die constantly. The system monitors each one’s health, replaces the sick ones automatically and migrates active customer sessions to a healthy exit without the customer noticing. Everything is visible in Prometheus metrics: how many exits are healthy, how many requests flow, where errors accumulate.
On top sits the classic SaaS layer: traffic-quota plans, Stripe subscriptions with idempotent webhooks, an admin panel and an audit trail for every session.
What I learned
That with infrastructure products, customers don’t pay for the feature — they pay to not think about it. All the value lives in the self-healing pool: the thing nobody sees as long as it works.