Duplicate hackathon detection

[ShantKhatri]

Summary

Catch duplicate submissions for the same event before they clutter the map.

Contexts

Needs a similarity check (name + date + location) at submission and scraper ingestion time.

Tasks

• Similarity check on new submissions against existing entries
• Flag likely duplicates for maintainer review instead of auto-approving
• Merge flow for maintainers to combine duplicates

Acceptance Criteria

• Near-duplicate submissions get flagged, not silently created
• Maintainer can merge two entries without losing submitter/scraper metadata
• Tests added

Area

backend

Difficulty

Advanced

[github-actions]

Hi @ShantKhatri,

Thanks for opening this issue.

Please reply with one of the following areas so the issue can be routed to the appropriate team member:

- /backend
- /web
- /mobile
- /devops

Once an area is selected, the corresponding label will be added automatically.

[himanshu051116]

Hi @ShantKhatri,

I am interested in working on this Advanced issue under GSSoC 2026. Before requesting assignment, I reviewed the current backend and found the existing Event model and event routes, but I could not locate the hackathon submission queue, scraper-ingestion flow, moderation state, or event-merge infrastructure referenced in the issue.

Could you please confirm:

1. Which existing submission and scraper paths should receive duplicate detection?
2. Whether another issue or branch is expected to introduce these missing flows first.
3. Whether the scope should include the required schema, moderation workflow, and merge endpoint, or only a reusable similarity-detection service.
4. Which metadata must be preserved when two records are merged.

Once the intended integration points are confirmed, I can provide a precise implementation plan covering normalization, similarity scoring, review thresholds, transactional merging, provenance preservation and regression tests.