𝗬𝗼𝘂𝗿 𝗦𝗰𝗿𝗮𝗽𝗲𝗿 𝗥𝗲𝘁𝘂𝗿𝗻𝘀 𝟮𝟬𝟬 𝗢𝗞 𝗮𝗻𝗱 𝗦𝘁𝗶𝗹𝗹 𝗟𝗶𝗲𝘀

𝗬𝗼𝘂𝗿 𝗦𝗰𝗿𝗮𝗽𝗲𝗿 𝗥𝗲𝘁𝘂𝗿𝗻𝘀 𝟮𝟬𝟬 𝗢𝗞 𝗮𝗻𝗱 𝗦𝘁𝗶𝗹𝗹 𝗟𝗶𝗲𝘀

The hardest bug to find is not a crash. It is a clean result with wrong data.

Your request returns 200 OK. Your selector works. Your dashboard looks fine. Still, your data lies.

Marketplaces are not simple lists. They change constantly.

Use these 7 checks to trust your data.

• Separate active and sold listings. Active listings show supply. Sold listings show demand.
• Track missing listings. Do not delete them. Log when a listing disappears.
• Split market country and seller country. They are not the same. Mixing them creates noise.
• Use required keywords. Search results often show nearby items. Filter them.
• Link price to item condition. Price means nothing without condition.
• Track price history. Changes are more useful than a single snapshot.
• Flag similar listings for review. Let a human verify the data.

I do not trust a scraper because it extracts rows. I trust it when it preserves context.

Which check do you use for your data?

Source: https://dev.to/datakaz/your-scraper-returns-200-ok-and-still-lies-7-marketplace-checks-i-use-51j7