Deal Monitor

The Problem

Real estate moves fast. By the time an investor sees a price drop, the deal is gone. Manual checking doesn't scale past a handful of properties.

The Solution

A monitoring service that runs around the clock:

• Go workers poll target sources on a tunable schedule, with backoff and jitter to stay polite.
• AWS SQS for fan-out, dead-letter handling, and at-least-once delivery semantics.
• EventBridge cron rules trigger heavier scans during high-signal hours.
• Webhook + email + in-app delivery so the alert reaches the investor wherever they actually are.
• De-duplication and rate-limiting so a single price drop doesn't generate 50 notifications.

Architecture

Clean event flow: poller → queue → differ → alerter → delivery. Each stage independent, observable, and replayable. Every alert can be traced from delivered notification back to the exact source observation that triggered it.

Outcome

Investors who set up monitors tend to act on the first alert they receive. The system has effectively replaced "checking listings every morning" for the investors who use it.