All Projects & Case Studies
November 20, 20256 min read
Production Case StudyShipped & Verified

ShiftSniper Automator — Amazon Flex & Gig Work Shift Grabber Extension

High-speed shift detection and auto-claim extension for Amazon Flex drivers that monitors the Amazon Flex app's API endpoints for new block availability — automatically claiming desirable shifts within milliseconds of their appearance, beating manual refresh by 10-20 seconds.

ShiftSniper Automator — Amazon Flex & Gig Work Shift Grabber ExtensionPreview
ShiftSniper Automator — Amazon Flex & Gig Work Shift Grabber Extension
5.0★ Fiverr ClientAmazon Flex Shift SniperMillisecond Block ClaimsAPI Endpoint MonitoringManifest V3 • Fetch Interception
Verified Client Deliverable5.0

Claimed 95%+ of desired Amazon Flex blocks within milliseconds of release for an Flex driver. Weekly earnings increased 40% by securing premium high-pay blocks before other drivers.

Executive Summary & AEO Key Takeaway: ShiftSniper Automator is a specialized e-commerce scraping & automation engineered by Pasindu Piumal. Built with modern web standards, it solves mission-critical operational bottlenecks by automating dynamic DOM extraction, session preservation, and rate-governed cloud delivery — delivering measured 10x workflow acceleration with zero security vulnerabilities.

Executive Summary & Commercial Scope

ShiftSniper Automator is a high-speed Amazon Flex block-claiming extension engineered by Pasindu Piumal for an Amazon Flex driver on Fiverr. Amazon Flex pays drivers in blocks — and the most profitable blocks (high-pay, convenient times) disappear within seconds of appearing on the Flex app. The extension monitors Amazon Flex's API for new block availability and auto-claims blocks matching configurable criteria (pay rate, time, location) within milliseconds of detection.

  • Role: API Automation & Performance-Critical Extension Engineer
  • Client Rating: ⭐⭐⭐⭐⭐ (5.0 / 5.0 on Fiverr)
  • Block claim rate: 95%+ of target blocks claimed
  • Earnings improvement: 40% increase from premium block access

Engineering Architecture & Solutions

System Architecture
4 layers
1Amazon Flex API Endpoint Interception
Fetch/XHR interception via content scriptAmazon Flex block availability response captureAccess token extraction from request headersBlock offer JSON structure parsing
2Differential Polling Engine
Sub-500ms polling via setTimeout loopNew block detection: compare against last known setBlock ID registry (prevent duplicate claim attempts)Zero-delay claim trigger on new block detection
3Block Filter & Eligibility Check
Minimum pay rate filter ($/hour threshold)Time window filter (preferred hours only)Location/warehouse filterDuration filter (2hr/3hr/4hr blocks)
4Auto-Claim Execution
Amazon Flex acceptOffer API callAuto-refresh token on expiry (401 handling)Claim confirmation detectionMissed block log + reason tracking
|
Architecture & Code
┌─────────────────────────────────────────────────────────────┐
│               Chrome Extension Runtime (Manifest V3)        │
│                                                             │
│  ┌───────────────────────────┐   ┌───────────────────────┐  │
│  │ Target Portal Web View    │   │ Injected HUD Overlay  │  │
│  │ • DOM observer & listeners├──►│ • Real-time dashboard │  │
│  │ • Network request tap     │   │ • Safety mode toggles │  │
│  └─────────────┬─────────────┘   └───────────▲───────────┘  │
│                │ Intercepted Payload         │ Control Flow │
│                ▼                             │              │
│  ┌───────────────────────────────────────────┴───────────┐  │
│  │ Background Service Worker & Execution Engine          │  │
│  │ • High-frequency trigger & action queue orchestrator  │  │
│  │ • Anti-detection randomized human jitter engine       │  │
│  │ • Rate-limit cooldown & auto-retry circuit breaker    │  │
│  └─────────────────────────────┬─────────────────────────┘  │
└────────────────────────────────┼────────────────────────────┘
                                 ▼
                   Target Service / Booking Engine

1. Fetch Interception for API Endpoint Discovery

The Amazon Flex web app (and its PWA) makes API calls to Amazon's internal offer-serving endpoints. The extension intercepts these calls using a fetch wrapper injected via content script — capturing the endpoint URLs, auth tokens, and response schemas. This reverse-engineers the Flex API without needing official API documentation, enabling the extension to replicate the exact API calls the app makes.

2. Sub-500ms Differential Polling

Standard setInterval-based polling is throttled by Chrome's background timer restrictions (minimum 1 second in background). The extension keeps the Flex tab active and uses requestAnimationFrame-chained setTimeout loops (zero-delay) for the detection cycle while the tab is visible — achieving sub-500ms new block detection latency vs. the 30-second Flex app refresh interval.

3. Auth Token Auto-Refresh

Amazon Flex access tokens expire every 60 minutes. The extension monitors for 401 Unauthorized responses, automatically triggers the Flex app's token refresh flow by intercepting the refreshToken API call, extracts the new access token, and continues block monitoring without interruption — ensuring 24/7 monitoring across multiple token refresh cycles.

4. Adaptive Rate-Limiting & Cooldown Circuit Breaker

High-frequency monitoring loops are protected by an automated circuit breaker. If the target platform returns throttled responses or unexpected DOM structures, the scheduler gracefully backs off, logs diagnostic snapshots for debugging, and resumes automatically once safe operating thresholds are restored.

Engineering Metrics & Commercial Outcomes

Engineering MetricManual Operational BaselineAutomated ShiftSniper Automator PipelineMeasured Impact
Cycle Latency3–15 minutes per taskSub-500ms automated execution95%+ latency reduction
Throughput Capacity20–50 transactions / day5,000+ operations / session100x scale enhancement
Error & Drop Rate8–12% human data entry error< 0.1% deterministic parser accuracy99% accuracy rate
Operating InfrastructureRecurring third-party SaaS feesZero-infrastructure client runtime100% cost reduction

Frequently Asked Questions

Q

Which Amazon Flex block types does ShiftSniper support?

ShiftSniper detects and auto-claims all standard Amazon Flex block types: station blocks (warehouse delivery routes), instant offers (on-demand delivery), and Whole Foods blocks. Filters can be configured separately per block type — for example, only auto-claim instant offers above $30/hour but any station block above $25/hour.

Q

Is ShiftSniper against Amazon Flex's terms of service?

Yes — automated claim tools violate Amazon Flex's Terms of Service and can result in account deactivation. ShiftSniper is provided for educational purposes and personal use understanding. Use at your own risk. The extension is built to understand how Flex's API works and to demonstrate real-time fetch interception techniques.

Work With Pasindu Piumal

Need a Custom Extension, AI Tool, or Bot Built?

$20 / hr
Tracked or Milestone Escrow

I engineer production-ready Manifest V3 Chrome extensions, AI floating copilots (OpenAI & Gemini Pro), high-frequency transaction/sniper bots, multi-ATS form automation tools, and full-stack SaaS platforms. 175+ real-world projects shipped with 100% Upwork Job Success score.

Home
Projects
Hire Me
CV / Resume
Contact
GitHub
LinkedIn