Amazon Shift Sniper — High-Frequency Booking & Slot Automation Chrome Extension

Amazon Automation Series — Over several months, Pasindu Piumal engineered 6 production Chrome extensions targeting Amazon's hiring and scheduling platforms. Each tackled a different layer of the same hard problem: making browser automation reliable under conditions specifically designed to prevent it — millisecond UI races, authentication friction, CAPTCHA walls, and active bot detection.

Project Overview

This is a showcase of a complete, battle-tested toolkit for Amazon workforce automation. Every project below is verified with a live Upwork contract, showing real client delivery across real adversarial conditions.

1. Amazon Shift Sniper — Real-Time Slot Monitor & Auto-Booker

A real-time monitoring extension that watches Amazon shift and interview availability pages, then clicks the moment a slot opens. Built with millisecond-level detection logic, dynamic retry intervals, and instant error-recovery when Amazon's "schedule no longer available" message appears.

Later evolved to support multi-profile broadcast control — a single trigger from a main profile fires a click signal across every connected browser session simultaneously, with automatic retry on failure.

Key Features:

• Sub-second slot detection across deep DOM layers
• Configurable click-interval tuning
• Multi-profile broadcast triggering across connected sessions
• Automatic retry logic on transient errors
• Dual-layer script injection (Isolated World + Main World)
• CloudFront 403 auto-cooldown bridge with jittered backoff

👉 View Upwork Contract — Amazon Shift Sniper

2. Amazon Hiring Automation with OTP & AI-Sync

Handles the full Amazon hiring application flow end-to-end — automated login, OTP capture (including 16-digit verification codes via IMAP fetching), and smart retry/restart logic when a verification attempt fails.

If an invalid-code error appears, the system waits, re-fetches the latest OTP from Gmail via IMAP, retries, and restarts the entire flow if needed — looping until success with no human intervention.

Key Features:

• Automated Gmail-based OTP retrieval via IMAP
• Self-healing verification loop with cooldown timing
• Full hiring flow automation: login → OTP → confirmation
• 16-digit Amazon verification code parsing
• Retry-on-failure with automatic flow restart

👉 View Upwork Contract — Amazon Hiring Automation + OTP

3. AI-Powered Chrome Extension + SaaS Dashboard

A broader project pairing a Chrome extension with a backend SaaS dashboard for real-time data synchronization. Demonstrates full-stack capability beyond pure browser automation — extension-to-server communication, live data pipelines, and a remote dashboard for monitoring extension activity.

Key Features:

• Extension-to-server real-time data sync
• Live dashboard for monitoring extension state remotely
• Full-stack architecture: MV3 extension + Node.js backend + dashboard UI

👉 View Upwork Contract — AI Extension + SaaS Dashboard

4. Amazon Real-Time Slot Tracker

A high-fidelity data extraction engine for Amazon hiring and scheduling pages, surfacing live statistics as the page updates in real time: job title, total orders, total positions, open positions, filled positions, soft matches, hard matches, and denied applications.

Key Features:

• Real-time stat extraction as the DOM updates
• Surfaces: total orders, open/filled positions, soft/hard matches, denied applications
• High-speed DOM polling with MutationObserver
• Live display panel with auto-refresh

👉 View Upwork Contract — Amazon Real-Time Slot Tracker

5. Amazon Portal Session Recovery — URL Auto-Repair

Automatically detects and repairs broken hiring-portal URLs and session states — timeout pages, 404 errors, and "no available shift" dead ends — by rewriting them to the correct job-confirmation path and retrying with a built-in cooldown if the broken state persists.

Key Features:

• URL pattern detection and automatic correction
• Timeout and 404 dead-end recovery
• Retry-with-cooldown logic for persistent broken states
• Zero manual user intervention required

👉 View Upwork Contract — Amazon Portal Session Recovery

6. AWS WAF & Amazon CAPTCHA Auto-Recovery (Shadow DOM Bypass)

The most technically demanding build in the series: a Shadow DOM–aware smart reloader designed to detect and recover from AWS WAF challenges and CAPTCHA interruptions without breaking the automation flow.

This required navigating deeply nested shadow roots and bot-detection countermeasures to keep the extension resilient under fully adversarial conditions — where Amazon actively deploys fingerprinting and behavioral analysis to detect and block automation.

Key Features:

• Shadow DOM traversal across nested roots
• AWS WAF challenge detection and recovery
• CAPTCHA interrupt detection + graceful reload
• Bot-detection countermeasure bypass
• Keeps automation flow intact without user involvement

👉 View Upwork Contract — AWS WAF & CAPTCHA Auto-Recovery

Engineering Architecture (Amazon Shift Sniper Core)

┌────────────────────────────────────────────────────────┐
│                   Amazon Hiring Portal                 │
│                                                        │
│   ┌─────────────────────────────────────────────────┐  │
│   │ Main World Injection Script                     │  │
│   │ • Inherits Native Portal Session Tokens & CSRF  │  │
│   │ • Bypasses CORS by executing in page context    │  │
│   └────────────────────────┬────────────────────────┘  │
│                            │ Sub-Second Shift Event    │
│                            ▼                           │
│   ┌─────────────────────────────────────────────────┐  │
│   │ Isolated World Content Script                   │  │
│   │ • Real-time Glassmorphic Status Dashboard       │  │
│   │ • Multi-Profile Broadcast Trigger               │  │
│   │ • Sound Alerts & Visual Shift Confirmation      │  │
│   └────────────────────────┬────────────────────────┘  │
└────────────────────────────┼───────────────────────────┘
                             ▼
┌────────────────────────────────────────────────────────┐
│      Manifest V3 Background Service Worker + Offscreen │
│                                                        │
│   ┌───────────────────────┐   ┌────────────────────┐   │
│   │ 403 CloudFront Bridge │   │ Infinite Keepalive │   │
│   │ Auto-Cooldown Jitter  │   │ Offscreen Audio API│   │
│   └───────────────────────┘   └────────────────────┘   │
└────────────────────────────────────────────────────────┘

Core Technologies (Across the Series)

• Chrome Extension API: chrome.scripting.executeScript(world: 'MAIN'), chrome.offscreen, chrome.storage, chrome.alarms, chrome.declarativeNetRequest
• Shadow DOM Traversal: Nested shadow root detection, WAF challenge recovery
• OTP Automation: IMAP email fetching, 16-digit code parsing, self-healing retry loops
• Frontend UI: React.js, Tailwind CSS, Lucide Icons, glassmorphic HUDs
• Resilience Engine: Exponential backoff, jitter calculation, MutationObserver DOM watcher, circuit breaker pattern

Engineering Metrics

Frequently Asked Questions