How We Built a Flight Price Tracker That Actually Works

Building a real-time flight price tracker is harder than it sounds. Here's what we learned scraping millions of fares, and what makes StalkMyTrip different.

The Problem We Set Out to Solve

Existing flight price trackers had the same flaw: they were slow. Most polled fare APIs on a 6–12 hour schedule and delivered alerts hours after a deal appeared. By the time a user tapped the notification, the fare was gone.

We set out to build something faster — and discovered quickly why the existing tools were slow.

Why Real-Time Flight Pricing Is Hard

Flight pricing is not a public API. Airlines and GDSs (Global Distribution Systems) charge for programmatic fare access, and the prices served through those APIs often lag behind what airlines publish on their own websites.

To get accurate, up-to-date prices, you need to query the same sources travellers use — and do it continuously, across hundreds of routes.

The challenges:

Rate limiting. Aggressive querying triggers blocks; too-gentle querying misses short-lived deals.
Geo-pricing. The same fare can return different prices depending on the IP country of the request. We normalise to a consistent market.
Currency. Prices must be compared in a single currency with a live exchange rate, not the display currency the airline chose.
Baseline accuracy. A 50% drop only means something if the baseline (the "normal" price) is accurate. A bad baseline produces false alerts.

How StalkMyTrip's Detection Engine Works

At its core, StalkMyTrip maintains a rolling 90-day price baseline per route-date combination. A new fare is only flagged as a deal if it's significantly below this baseline — not just cheaper than yesterday.

Alerts are classified into tiers:

Good deal — 20–40% below baseline
Great deal — 40–60% below baseline
Error fare — 60%+ below baseline (triggers an immediate push, not just email)

Users set their own threshold per alert. The classification is shown in the notification so you know at a glance whether you're looking at a routine dip or a once-a-year anomaly.

What We're Building Next

The tracker currently covers flights. We're extending the same continuous-monitoring approach to hotels and bus routes, because the cheapest trip isn't always about the flight — it's about the total cost of getting there.

If you have a route you'd like us to prioritise, send it to us via the feedback link in the app.