How do I integrate DBA.dk, Trendsales, and Saxo.com product feeds?

Three big Danish marketplaces with very different audiences, we’ve built feeds for all three:

• DBA.dk, Denmark’s biggest C2C / classifieds marketplace (Schibsted-owned, ~2.5M monthly users). Best for second-hand, refurbished, off-season inventory, and bulk pieces. Product feed via DBA Business / DBA Plus account, XML format spec from DBA Erhverv. We map Magento catalog_product → DBA listings with image / price / condition / category mapping.
• Trendsales, Vinted-style fashion resale, dominant in 18-35 Danish women + men’s fashion (especially second-hand premium). Owned by Adevinta. API-based feed for verified shops + Trendsales Pro account. Particularly relevant for fashion brands wanting to capture the resale loop.
• Saxo.com, Denmark’s biggest online bookstore + a major media / film / music seller, owned by JP/Politikens Hus. Marketplace via Mirakl-style platform; product feed via Saxo Partner API, ISBN-driven for books.

Implementation pattern: scheduled cron exporter (every 30-60 min for price/stock; daily for full catalogue), per-marketplace transformer (different XML / JSON schemas), order-import webhook back into Magento as “DBA / Trendsales / Saxo” sales channel for unified fulfilment.