Backend Development for Multi-Platform Marketplace Alert

@KESHAVINFOTECH

Hi, This is mainly a reliability challenge: fast listing detection, clean deduping, and keeping Facebook sessions alive without breaking the alert flow. Since your dashboard already exists, the safest approach is a backend service that plugs into your current JSON format and handles scraping, filtering, alerting, and account rotation. I’ve built backend scrapers and notification flows in Node.js where session handling, retry logic, and data normalization were critical. My first priority would be the polling engine for each source, followed by the dedupe store, then the REST endpoint and FCM trigger so your app only receives fresh listings. I would also isolate Facebook rotation and proxy handling so one blocked session does not affect the system. I’d structure this around stable workers for Facebook, OfferUp, and eBay, with logging, rate control, and deployment on Railway or Render. One key question is how duplicate alerts should work across cities and keywords: once per user search, or once globally? If this matches your needs, I’d be glad to discuss the workflow and next steps in Freelancer chat or video call, 11 AM–8 PM IST. Regards, Ghanu & Samir KESHAV INFOTECH

@ykarora26

With experience in backend development and API integration, I understand the need to build a real-time marketplace alert system that scrapes Facebook Marketplace, OfferUp, and eBay for new listings. My previous work involves creating similar scraping systems and REST API integrations. Can you provide more details on the specific data fields required for the JSON format in your current Apify setup? Regards, Yogesh Kumar

@kamran2012

This looks like a great fit, I will build the scraping backend for Facebook Marketplace, OfferUp, and eBay, with deduplication and FCM alerts, all matching your existing JSON format. 1. Yes, I have scraped Facebook Marketplace using Playwright stealth with GraphQL interception and rotating cookie sessions. 2. I will rotate warmed account cookies automatically on detection, with cooldown logic and proxy cycling through your Webshare ISP pool. 3. Realistic timeline: 10 days for all three platforms deployed and tested on Railway. Do you want eBay polling at 60s from day one, or should I prioritize Facebook stability first? Ready to start whenever you are. Kamran

@rahuliitm69

Hi there, I got everything. As you already have the dashboard, mobile app, API format, and infrastructure ready, most of the groundwork is already done. Now I will build the complete scraping and alert backend that plugs directly into your existing system without affecting the current frontend. For me, Facebook Marketplace is the core because that's where session handling, cookie rotation, ISP proxy management, GraphQL interception, and anti-bot detection need to be handled carefully. I would first build the common backend architecture with scheduling, deduplication, REST APIs, and FCM, then integrate Facebook, OfferUp, and eBay one by one so the entire system remains stable and scalable as you add more marketplaces in the future. Once everything is integrated, I will deploy it on Railway/Render, thoroughly test all three platforms, provide the complete source code, README, proxy/cookie management guide, and hand over 100% ownership of the project. I have a few questions regarding the expected number of concurrent users, keyword monitoring limits, and how you want to manage multiple Facebook accounts. I would request we connect once so we can discuss these points, after which I'll share a detailed implementation plan with the development phases and timeline. Thanks, Rahul A.

@ZohaibRoy

⭐⭐⭐⭐⭐ Build a Real-Time Marketplace Alert System for Facebook, OfferUp, eBay ❇️ Hi My Friend, I hope you are doing well. I reviewed your project requirements and see you are looking to build a backend system for monitoring listings. Look no further; Zohaib is here to assist you! My team has completed over 50 similar projects for alert systems. I will create a robust scraper that integrates seamlessly with your existing Node.js dashboard, ensuring instant notifications for new listings. ➡️ Why Me? I have 5 years of experience in building web scrapers and alert systems, focusing on platforms like Facebook and eBay. My expertise includes session management, API integration, and push notifications. Additionally, I have a strong grip on Node.js and Playwright, ensuring efficient execution of your project. ➡️ Let's have a quick chat to discuss your project in detail and I can provide samples of my previous work. I look forward to this opportunity! ➡️ Skills & Experience: ✅ Web Scraping ✅ Node.js ✅ Playwright ✅ API Development ✅ Push Notifications ✅ Data Deduplication ✅ Session Management ✅ Anti-Bot Strategies ✅ RESTful Services ✅ JSON Handling ✅ Firebase Cloud Messaging ✅ Debugging & Testing Waiting for your response! Best Regards, Zohaib

@starttechno

I understand you need a backend scraping system for Facebook Marketplace, OfferUp, and eBay that monitors new listings by city and keyword, deduplicates results, exposes a REST API matching your current Apify JSON format, and sends FCM push notifications—all without touching your existing Node.js dashboard or mobile app. My technical approach: I'll build this using Node.js with Express for the REST API, MongoDB for storing seen listing IDs and user preferences, and Redis for caching recent listings to enable fast deduplication. The system will run on Railway or Render with scheduled jobs using node-cron. For Facebook Marketplace, I'll implement Playwright with stealth plugins to manage warmed account sessions using cookie files you provide. The scraper will intercept GraphQL API responses to extract listing data, rotate between multiple account sessions if one gets blocked, and use your Webshare ISP proxies. I'll configure polling every 2-5 minutes with city and keyword filters. For OfferUp, I'll use Playwright with lightweight scraping to extract listings filtered by keyword, location, and price range, polling every 2-3 minutes. For eBay, I'll leverage their RSS feed API for newly listed items, filtering by keyword, location, and price with 60-second polling intervals. Muhammad Saad

@ambientinfotech

Hi, I don't just write code—I build reliable solutions that solve real business problems. Whether it's automation, APIs, web applications, AI, or backend development, I can deliver exactly what you're looking for. Looking forward to working with you. Thanks,

@corpmember29

**I WILL BUILD A SCALABLE, REAL-TIME MARKETPLACE ALERT BACKEND THAT DELIVERS NEW LISTINGS WITHIN MINUTES.** With 12+ years of experience in Node.js, Python, Playwright, web scraping, proxies, and cloud deployment, I've built data extraction and automation systems for protected platforms with reliable anti-bot strategies. **1. Experience:** Yes. I've worked on protected platforms using Playwright, persistent browser profiles, cookie/session management, proxy rotation, request interception, and stealth techniques to maintain stable scraping. **2. Blocking Strategy:** I'll use warmed Facebook accounts, rotating ISP proxies, cookie rotation, randomized behavior, rate limiting, automatic session recovery, and health monitoring. If an account is blocked, the system will seamlessly switch to another account while flagging the blocked session for replacement. **3. Timeline:** 10–14 days for Facebook, OfferUp, and eBay integration, REST API, FCM notifications, deployment on Railway/Render, documentation, testing, and 2 weeks of post-delivery support. The solution will include deduplication, scheduled polling, JSON output matching your existing API, GitHub delivery, deployment, and comprehensive documentation. Let's discuss your current backend and get this running reliably.

@technologiesit

Being a Full Stack Developer for over a decade, I've proficiently built and integrated numerous scraping and automation tools. From your project description, I can see you are clearly looking for someone skilled in Node.js, with extensive experience in building scrapers for protected platforms like Facebook Marketplace. Successfully developing projects with similar requirements makes me uniquely equipped for this task. For example, to handle Facebook blocking the scraper specifically, I have employed similar fallback strategies before. My approach involves using multiple warmed Facebook accounts(with ISP proxies) and session management through Playwright to tackle any anti-bot detection measures. Additionally, being adept in PHP further broadens my understanding of backend development tools making it convenient for me to cater to both your present Node.js infrastructure as well as incorporate the necessary features for eBay and OfferUp scrapping. Time is value, and I fully appreciate the need for timely delivery without compromising on quality. Committed to your project's success, I assure you prompt execution without unnecessary delay. Within 14 days, I will deliver a tested system that successfully monitors all three platforms and sends notifications promptly via Firebase Cloud Messaging. Choosing me would mean choosing expertise, reliability, and long-term support in building smart digital solutions exclusive to your requirements.

@krupnovdenis

Hello! We can build the backend alert system for your existing dashboard and app. 1. Have you already defined the exact API response format for new listings? 2. What is the first platform you want us to prioritize for delivery? — About us We are dZENcode – a full-cycle IT company for digital product development: from design and programming to integrations and post-release support. We build projects from scratch and also work on existing solutions that need further development, improvements, or technical support. You can find detailed information about our services and rates on our official website: https://dzencode.com. Please review it – after that, we can discuss the details and agree on the next step. ⚠️ After clarifying all details, we will define the scope, the suitable cooperation format – task-based, outsourcing, or outstaffing – and the final cost. Projects are guaranteed to reach release with us: • 10+ years providing IT services; • 90+ in-house specialists; • 250+ public reviews since 2015; • We support products under SLA after launch; • We work under NDA and a company contract!

@rbtech1984

Hi There!!! ★★★★ (Production-ready multi-platform scraper with real-time alerts, FCM, and scalable architecture) ★★★★ I’ve read your requirements carefully and understand you already have the dashboard and mobile app ready. You need a robust backend that monitors Facebook Marketplace, OfferUp, and eBay, deduplicates listings, sends FCM notifications, and integrates with your existing REST API without touching the frontend. ⚜ Facebook Marketplace scraper with Playwright ⚜ OfferUp & eBay monitoring ⚜ Listing deduplication system ⚜ REST API integration ⚜ FCM push notifications ⚜ Railway/Render deployment ⚜ Documentation & 2 weeks support Yes, I've worked on protected platforms using Playwright, rotating sessions, cookie management, stealth techniques, and proxy rotation to maintain stable scraping. To reduce Facebook blocking, I'll implement warmed account rotation, ISP proxies, automatic session switching, retries, and health monitoring with graceful failover. A realistic timeline is 10–14 days including deployment, testing, and documentation. I build scalable Node.js/Python scraping backends with clean code and ongoing support, and I'd be happy to discuss your existing API structure and get started. Warm Regards, Farhin B.

@Tanmoy236

Hi There! I specialize in backend development and web scraping with 9+ years of experience building scalable real-time data collection systems, REST APIs, and notification services. Here's how I can help: 1. Build Playwright-based scrapers for Facebook Marketplace, OfferUp, and eBay with deduplication. 2. Integrate REST APIs, FCM push notifications, and Railway/Render deployment. 3. Implement proxy rotation, session management, and documented, scalable architecture. Regarding your questions: 1. Yes, I've worked with protected platforms using Playwright, session persistence, proxies, and request interception. 2. I'll use rotating warmed accounts, ISP proxies, cookie rotation, retry logic, and monitoring to minimize blocking. 3. I can deliver a fully tested and deployed solution in approximately 10–14 days. Does your current Node.js dashboard already expose the API contract I should match exactly?

@toriquldev123

Hello dear, Greetings from MD. Toriqul Islam! We are a dedicated Web Design & Development team with over 10+ years of industry experience. I’m Engineer Toriqul Islam, an experienced Computer Science & Engineering graduate from RUET. We specialize in building modern, scalable, and user-friendly digital solutions tailored to business needs. What I Offer We help businesses grow online by delivering: • Clean, modern, and responsive website designs • High-performance and scalable web applications • User-focused UI/UX for better engagement and conversion My Technical Expertise We work across a wide range of technologies, including: • Frontend: HTML5, CSS3, Bootstrap, JavaScript, jQuery, Angular, React • Backend: Node.js, PHP, Laravel, .NET, CodeIgniter, Ruby on Rails, Python • CMS & Platforms: WordPress • Database: MySQL, MongoDB • Mobile Development: React Native, Flutter, and more Why choose me? ✔️ Clean, optimized, and well-documented code ✔️ Reusable and scalable components ✔️ On-time delivery with complete requirement fulfillment We are confident in our ability to turn your ideas into a powerful digital product. Let’s discuss your project and make it a success. Looking forward to working with you! Best Regards, Md. Toriqul Islam

@yuliussmayoru

I WILL BUILD THIS AS A STABLE ALERT BACKEND WITH CLEAN DEDUPING AND FAST NOTIFICATIONS, NOT A SCRAPER THAT WORKS FOR A FEW DAYS THEN DIES. Hello! The real challenge here is keeping three different marketplace sources normalized into one clean alert pipeline while protecting speed, reliability, and your existing API format. I can build the backend only, plug it into your current Node.js dashboard, and keep the frontend untouched. For eBay, I would use the native RSS feed, poll every 60 seconds, sort by newest, and normalize each item into your exact JSON structure. For OfferUp, I would build a lightweight Playwright worker with keyword, city, and price filters, plus retries, logging, and dedupe checks. For Facebook Marketplace, I would use managed sessions, account cookie rotation, proxy configuration, block detection, and safe fallback handling so the system pauses unhealthy sessions instead of crashing. All listings will pass through a MongoDB or PostgreSQL seen listings store, then trigger Firebase Cloud Messaging only for genuinely new items. I will deploy on Railway or Render, add cron based workers, provide a README for cookies, proxies, env vars, and include two weeks of bug fixes after handover. Warm regards, Yulius Mayoru

@fullstack0407

I have read your job post and understand that you need a backend service that monitors multiple marketplaces, detects genuinely new listings, and integrates with your existing Node.js dashboard and mobile app. I have experience building scraping and automation backends, REST APIs, Playwright-based workflows, data deduplication, scheduling, deployment, and notification systems. I can build a modular backend with clear logging, proxy/account configuration, deployment documentation, and GitHub version control. Where integrations involve third-party platforms, I would implement them in a way that respects each platform's available interfaces and applicable terms, while keeping the architecture scalable so additional marketplaces can be added later.

@johnallenvillan1

Hi there, Facebook Marketplace blocking, session rotation, and reliable 2-5 minute polling are the real risks here. I’ve spent the last 4 years solving exactly this type of problem: protected-platform scraping, deduplication, and alert backends that stay stable in production. I’ve delivered a Playwright-based marketplace monitor with proxy rotation and account failover, and built a Node.js alert pipeline that pushed fresh results into an existing dashboard API without frontend changes. The hard part isn’t fetching listings once; it’s keeping IDs clean, avoiding duplicate alerts, and surviving block events without breaking your polling contract. I’ll build the backend so each source returns your exact JSON shape, with dedupe persisted across runs and FCM notifications triggered only on genuinely new listings. I’ll implement Facebook with warmed cookies, ISP proxies, GraphQL response interception, and account rotation. OfferUp will run as a lightweight Playwright poller, and eBay will use RSS with 60-second checks. I’ll package it for Railway or Render, push everything to your private repo, and include a README covering cookie rotation, proxy setup, and deployment. Best regards, John allen.

@Elexoft

Hi, We have already built data scraping, monitoring and alert systems with API integrations and automated notifications so we are confident we can help with your project. Answer to your questions: 1. Yes, we have worked with protected platforms and used Playwright, session persistence, proxy rotation and browser fingerprint management to maintain stable scraping workflows. 2. If Facebook blocks an account, we will automatically rotate to backup accounts and proxies while monitoring account health. Additional safeguards can be added to reduce detection risks. 3. Our realistic timeline for all three platforms, API integration, deployment and testing is approximately 4 - 6 weeks depending on account readiness and testing requirements. We would be happy to discuss the details and get started right away. Best Regards, Elexoft

@maryam951

As a seasoned developer with a focus on web scraping, I'm confident in my ability to build the backend system you're seeking. My understanding of both Node.js and PHP aligns perfectly with your project's requirements. Additionally, my proficiency in web scraping, specifically on protected platforms such as Facebook Marketplace, makes me the ideal candidate for the job. Best regards, Maryam Abbas

@muneeb6767

I have experience building high-performance web scraping and real-time alert systems with Playwright, Node.js/Python, proxy rotation, REST APIs, Firebase notifications, and scalable data pipelines, and can deliver a reliable backend with deduplication, monitoring, and seamless integration into your existing dashboard.