Development of Product Moderation for Marketplace Sellers
Without moderation, a marketplace becomes a dump: duplicates, prohibited categories, inflated specs, photo plagiarism. A moderation system must balance between verification speed and filtering quality — strict manual review slows seller onboarding, automatic filtering misses violations.
Product Models and Statuses
products
status: draft | pending | approved | rejected | suspended
moderation_comment: text (nullable)
moderated_by: user_id (nullable)
moderated_at: timestamp (nullable)
auto_moderation_score: float (0–1)
Transitions: seller publishes (draft → pending) → moderator or automated system checks → approved or rejected. Possible suspended — product was approved but later blocked (complaint, violation).
Moderation Queue for Moderators
Moderator interface is a separate admin panel section with filters by category, seller, submission date. Moderator sees:
- Product images (gallery, zoom), name, description, attributes
- History of previous versions and reasons for previous rejections
- Seller rating and number of already-approved products
- Buttons: approve / reject (with mandatory comment) / request changes
Hot keys and batch approval speed up work: moderator can approve 10–20 similar products from one seller with one action after initial review.
Automatic Pre-Moderation
Before reaching moderator queue, product undergoes automatic checks:
- Duplicates by name/image — search by image hash (perceptual hash) and text cosine similarity
- Prohibited categories and words — forbidden terms dictionary, regexp check
- Image quality — minimum resolution 800×800, no competitor watermarks (TensorFlow Serving ML-model)
- Price correctness — price not below category cost of goods sold, not exceeding market maximum by N%
- Card completeness — mandatory category attributes filled
Products with high auto_moderation_score (>0.85) can pass auto-approval for verified sellers.
Appeals and Corrections
After rejection, seller receives detailed comment and can fix the product. Corrected version goes to separate "re-review" queue with change markers — moderator sees diff between versions.
Seller Notifications
- Email/push on status change
- List of rejected products with reasons in personal account
- Pending review counter on seller dashboard
Moderation Metrics
Useful to track: average approval time, % rejected by category, moderator workload by hour. Helps optimize process and identify problematic sellers.
Development timeline: 3–4 weeks for complete module with automatic pre-moderation and moderator interface.