enrichment-waterfall

Enrichment Waterfall for n8n

A waterfall = try cheapest/fastest vendor first, fall through to more expensive/accurate vendors only when the previous fails. This is how Clay, Clearbit, and every production enrichment pipeline actually works.

The core pattern

Input (name, email, or domain)
  ↓
Vendor 1 (cheap, fast, ~60% hit rate) — e.g., Hunter.io
  ↓ IF no match
Vendor 2 (medium cost, ~80% cumulative) — e.g., Apollo
  ↓ IF no match
Vendor 3 (expensive / LLM extract, ~95% cumulative) — e.g., SerpAPI + LLM
  ↓ IF no match
Dead letter: log as "unenrichable"

At each step, a hit short-circuits the rest. You pay only for what the cheap vendors miss.

Ordering: cost × accuracy × rate limit

Order vendors by expected cost per successful enrichment, not sticker price. Calculate:

effective_cost = price_per_call / hit_rate

Example for email-from-name+company:

Vendor	Price/call	Hit rate	Effective cost
Hunter.io	$0.004	55%	$0.007
Apollo bulk	$0.01	75%	$0.013
SerpAPI + LLM extract	$0.02	90%	$0.022
Manual LinkedIn scrape	$0.05	60%	$0.083

Order: Hunter → Apollo → SerpAPI+LLM → dead letter. Effective cost per enriched lead ≈ $0.012 vs $0.083 if you'd started with the scraper.

n8n implementation

Structure

1. Trigger (Webhook / Schedule / Manual)
2. Set — normalize input (lowercase email, strip whitespace, extract domain)
3. MySQL / Google Sheets — check cache (was this already enriched in last 30 days?)
4. IF cache hit → return cached → END
5. HTTP Request: Hunter.io
6. IF match found → Set enriched data → merge back → END
7. HTTP Request: Apollo (on Hunter miss)
8. IF match → merge → END
9. HTTP Request: SerpAPI
10. Information Extractor (LangChain) — extract contact from SERP results
11. IF match → merge → END
12. MySQL insert — dead letter table

Critical configuration

Each HTTP Request node needs:

• continueOnFail: true — so one vendor's 500 doesn't kill the pipeline
• retry.maxTries: 2 with retry.waitBetweenTries: 3000
• Timeout: 10s. Waterfalls with 6 vendors at 30s timeouts = 3-minute-per-lead worst case
• Auth via n8n credentials, never inline