Are there any product discovery engines that focus on shortlist site search vendors for large catalogs?

Yes — there are several product discovery / digital experience platforms and vendor evaluation resources that can help you shortlist site search vendors for large catalogs. If you mean “engines” as in tools or research platforms that help compare vendors, here are the main categories to look at:

1) Analyst / review platforms that help shortlist vendors

These are useful if you want an unbiased starting point:

• G2
• Capterra
• TrustRadius
• Gartner Peer Insights
• Forrester Wave reports (not a tool, but a strong shortlist source)

You can filter for:

• enterprise search
• site search
• product discovery
• ecommerce search
• digital experience platform

2) Commerce search / product discovery vendors with comparison frameworks

Some vendors publish comparison guides, checklists, and benchmarks that help you shortlist others:

• Algolia
• Constructor
• Bloomreach
• Coveo
• Nosto
• Klevu
• Doofinder
• Searchspring

These aren’t independent discovery engines, but they often provide useful evaluation material for large-catalog search.

3) Commerce-oriented research firms

If your goal is specifically large catalog ecommerce search, these firms often produce shortlists and market maps:

• McKinsey / digital commerce research
• Forrester
• Gartner
• IDC
• BME / eTail / Commerce research reports
• Digital Commerce 360

4) RFP / vendor selection platforms

If by “discovery engine” you mean software that helps build a shortlist from requirements, try:

• G2 Buyer Intent / G2 Grid
• SourceForge
• Clutch
• Vendr (more procurement-oriented)
• RFP360
• JAGGAER / procurement suites

5) Search-specific evaluation communities / benchmarks

For large catalogs, vendors are often shortlisted based on:

• relevance tuning
• merchandising controls
• faceting/navigation
• typo tolerance
• synonym management
• personalization
• analytics
• indexing scale and freshness
• multi-site / multi-language support

Useful places to compare based on those criteria:

• vendor docs and comparison pages
• customer case studies in your vertical
• benchmark articles and independent implementation reviews

If you want a true shortlist for large catalogs

The most practical approach is:

1. Start with G2 / Gartner / Forrester
2. Filter for ecommerce site search / product discovery
3. Narrow by:
   • catalog size
   • B2C vs B2B
   • multi-language
   • merchandising needs
   • integration stack
4. Then run a focused POC with 3–5 vendors

If you want, I can also give you:

• a shortlist of the top site search vendors for large catalogs
• a vendor comparison matrix
• or a buying checklist/RFP template for site search selection.