The challenge#
The used electronics market in Hungary is extremely active. Hardverapro.hu is the country's largest classified ad platform for tech products: GPUs, processors, monitors, laptops, phones, networking gear — essentially anything IT-related. Thousands of listings appear daily, and demand is consistently high, especially for products with a strong price-to-value ratio.
The problem is that the best deals sell out within minutes. A realistically priced RTX 4070 GPU can attract 5-8 inquiries within the first 10-15 minutes. A ThinkPad laptop in good condition listed at 70% of market price? The first response typically arrives within 3-5 minutes. If you're not among the first to respond, you don't stand a chance — sellers usually go with the first serious buyer.
The manual approach: opening the site every hour, scrolling through fresh listings, comparing prices, filtering for relevant results. This is not only time-consuming but unreliable — you can't monitor continuously, and the best deals often appear during work hours, late at night, or on weekends when you're not browsing.
The real problem: Hardverapro.hu doesn't offer a detailed notification system. There's a basic saved search feature, but it doesn't filter by price, exclude keywords (e.g., "broken", "for parts"), filter by location, or send instant push notifications. Anyone seriously looking for a specific product at a good price has no option other than manually checking the site on a regular basis — or automating the process.
Web scraping — the automated collection of data from websites — is legal in Hungary and the EU, as long as a few basic rules are followed. Both EU court rulings and Hungarian legal precedent have confirmed that automated processing of publicly available data does not violate copyright, provided the data collection doesn't aim to copy the entire database and doesn't harm the service provider.
AproRadar follows these principles:
- We only collect publicly available data — exclusively listings that anyone can view on Hardverapro.hu without registration
- We don't overload the server — we maintain reasonable query frequency (at most a few requests per minute) and respect robots.txt rules as well as rate limits
- We don't bypass security mechanisms — we don't automatically solve CAPTCHAs, log into user accounts, or use proxy rotation to avoid blocking
- We don't store personal data — we only process the public content of listings: title, price, link, category. We don't collect or store advertisers' personal data (phone number, email)
- GDPR-compliant operation — since we don't process personal data, the data protection regulation doesn't impose additional requirements on how the system operates
AproRadar therefore only monitors public listings, with minimal server load, and temporarily stores only the business data of listings (title, price, category, link) for deduplication purposes.
The solution in detail#
AproRadar is a simple yet highly effective monitoring system. We didn't overcomplicate it — it does exactly what's needed, and does it well.
Setting up search criteria
The user defines once what products they're looking for and under what conditions. The system stores these parameters and applies the filters on every run. This step is the most important: the more precise the filter settings, the fewer irrelevant results arrive, and the faster the user can respond to truly relevant listings.
- Keywords: E.g., "RTX 4070", "iPhone 15", "ThinkPad T14"
- Price range: Minimum and maximum price (e.g., 100,000 - 200,000 HUF)
- Category: Hardverapro category filtering (e.g., GPUs, Laptops)
- Excluded words: Things we DON'T want (e.g., "broken", "for parts", "trade")
- Location: Optional geographic filter (e.g., only Budapest-based sellers)
Multiple searches can be configured in parallel — for example, you can monitor GPUs AND monitors simultaneously. There's no upper limit: someone searching for 15 different products at once sets up 15 filters and receives separate notifications for each.
Custom Python script with scheduled execution
The core of the system is a custom Python script hosted on the Apify platform. Apify is a cloud-based scraping platform that provides reliable scheduling, automatic restarts, and detailed execution logs — no need to maintain your own server. The script runs at regular intervals (every 15 minutes by default), but can be set to 5-minute cycles on request.
During each run, the script:
- Scans Hardverapro's relevant categories and retrieves new listings
- Compares every new listing against all active search criteria (keyword, price, category, location, excluded words)
- If a match is found, stores the result and forwards it to the n8n notification workflow
- Tracks previously seen listings in an internal database so it never sends duplicate notifications
The script is intelligent: it doesn't just search for keywords in the title but also analyzes the full text of the listing to filter out misleading results. For example, a listing like "Looking for an RTX 4070" is a buying request, not a selling offer — the system recognizes this and filters it out. Similarly, "Would trade for an RTX 4070" type listings are also ignored if the user is only interested in purchase offers.
Telegram notification — instant, detailed
When the system finds a match, the n8n workflow immediately sends a Telegram message to the user. Telegram was a deliberate choice as the notification channel: it appears instantly as a push notification on the phone, doesn't get lost among emails, and the listing link can be opened with a single tap. No need to install a separate app beyond Telegram, and the user can even receive notifications in a group if multiple people are searching together.
The message includes:
- The listing title and price — immediately visible whether it's worth clicking
- The seller's name and rating — for a quick reliability check
- A preview photo (if the listing contains an image) — for a quick assessment of the product's condition
- A direct link to the listing — one click, and the user can already write the first message to the seller
- Which search criteria the listing matched — especially useful when multiple searches are running simultaneously
Before and after#
- Hourly manual browsing on Hardverapro.hu
- No one monitoring during work hours and at night
- Many missed opportunities — sold out by the time you see it
- No price filter, no negative keyword filtering
- 30-60 minutes of daily browsing
- Automatic check every 15 minutes
- 24/7 monitoring — nights and weekends included
- < 1 minute alert on new listings
- Detailed filtering: price, keyword, category, location
- 0 minutes browsing — you only see the relevant listings
Telegram notification — New match
🔔 New listing — RTX 4070 search
ASUS Dual RTX 4070 Super OC 💰 189,000 HUF (range: 100,000 - 220,000 HUF ✅) 👤 Seller: TechMaster92 (⭐ 4.8, 127 reviews) 📍 Budapest, District XIII 📅 Posted: 2 minutes ago
"Selling ASUS Dual RTX 4070 Super, 2 months old, with box and warranty. In-person pickup in Budapest."
🔔 New listing — ThinkPad search
Lenovo ThinkPad T14 Gen 3 — Ryzen 7, 16GB, 512GB 💰 145,000 HUF (range: 80,000 - 180,000 HUF ✅) 👤 Seller: LaptopGuru (⭐ 4.9, 203 reviews) 📍 Debrecen 📅 Posted: 5 minutes ago
"Replaced company laptop, excellent condition T14 for sale. Factory warranty until September 2026. Battery health at 92%. Pickup in Debrecen or shipping available."
Search: "RTX 4070" | Price: 100-220k HUF | Category: GPUs Search: "ThinkPad T14" | Price: 80-180k HUF | Category: Laptops
Results in numbers#
| Metric | Before | After |
|---|---|---|
| Monitoring coverage | ~3-4 hours/day (manual) | 24/7 automatic |
| Alert time | Next time I check | < 1 minute |
| Missed opportunities | 5-10 per day | ~0 |
| Manual browsing time/day | 30-60 minutes | 0 minutes |
| Simultaneous searches | 1-2 (what I can keep in my head) | Unlimited |
The user is among the first to learn about new listings and can respond immediately. The system runs 24/7, even when the user is sleeping, working, or doing something else. In practice, this means they can respond to the best deals within minutes of the listing appearing — which on Hardverapro.hu often means the difference between success and "sorry, already sold."
How to apply this in your business#
The concept behind AproRadar — automated market monitoring and instant alerts — is applicable in virtually any business context. The technical foundations are the same: data collection (Apify), processing and filtering (n8n), notification (Telegram, email, or Slack). The specific logic changes, but the architecture is reusable. Some concrete examples:
- Competitor monitoring: Automatically track when the competition changes prices, launches new products, or starts new promotions on their site. The system compares previous and current states and only notifies about changes.
- Procurement opportunities: If your company regularly purchases used machinery, equipment, or raw materials, the monitoring system automatically filters the market based on specified criteria — whether it's used CNC machines, office furniture, or delivery vehicles.
- Job market monitoring: For HR teams: monitoring specific positions, skills, or geographic locations on job portals. Get notified instantly when a candidate with the desired profile appears on the market.
- Real estate monitoring: Monitoring real estate listings on property platforms with custom criteria — price, location, square footage, number of rooms — and instant alerts before others snatch up the good deals.
- Tender monitoring: Automatic monitoring of public procurement tenders, EU grants, or industry-specific tenders. The system filters by topic, amount, and deadline, and immediately notifies the relevant colleague.
- Product availability monitoring: If a specific product is frequently out of stock (limited edition items, popular electronics), the system watches webshops and alerts you as soon as the product is back in stock.
If you'd like automated market monitoring for your business, book a free consultation.
Tech stack#
| Tool | Role |
|---|---|
| n8n | Workflow scheduling and notification delivery |
| Apify | Custom Python script for Hardverapro scraping |
| Telegram | Instant push notifications to the user |