Configurable Radius Instead of Magic Numbers (Configurable Radius Instead Of Magic Numbers)

Configurable Radius Instead of Magic Numbers

A five-kilometer example rule must still be data-driven so yards and corridors can differ.

km_metric from API, not const RADIUS = 5

5 km örnek kuraldır; kod sabiti değil.

Concepts, defined where they first appear

📦 Geofence
A geographic boundary on the map; for circles: center + radius.

📦 Telematics Feed
External source of vehicle position and ignition signals.

📦 km_metric
Radius in kilometers from the API; converted to meters on the map.

📦 Operational State
The waiting state operators decide — distinct from raw GPS.

Teams that blur these concepts confuse UI state with integration truth.

Shape of the problem

A five-kilometer example rule must still be data-driven so yards and corridors can differ.

km_metric from API, not const RADIUS = 5

The split that works

5 km örnek kuraldır; kod sabiti değil.

km_metric from API, not const RADIUS = 5
        ↓
   explicit contract

Where production breaks

Incidents grow when radius, identity, or deploy assumptions stay implicit. Make the contract visible and reversible.

The mappings that get confused most often

❌ One app is always safer
✓ Without clear boundaries, one app is more fragile

❌ Keep config hardcoded
✓ Radius, remote URLs, and expose paths are operational contracts

❌ Vendor/API truth is UI state
✓ Vendor feed is evidence; ops state is a decision

A checklist for auditing your own system

1. Write the ownership boundary for this surface in one sentence.
2. If this contract changes, who deploys?
3. On timeout or vendor delay, what does the UI show?
4. Do you test embedded and standalone paths separately?
5. Deny-list check: any vendor/domain leakage in copy?

What to take away from this part

1. Contracts must be visible: expose paths, radius, ticket state, or remote URLs.
2. The gap between UI and external systems is a design choice, not a bug.
3. Independent deploy means independent rollback.

The boundary you hide will find you in production.