Add Neo4j-powered Business Leader Network

README.md

@@ -1,5 +1,125 @@
-# Ruby on Rails Tutorial: first application
+# Business Leader Network
 
-This is the first application for the
-[*Ruby on Rails Tutorial*](http://railstutorial.org/)
-by [Michael Hartl](http://michaelhartl.com/).
+A graph-powered B2B sales and marketing intelligence application built with Ruby on Rails and Neo4j — inspired by [Kantwert's presentation at GraphConnect](https://neo4j.com/blog/cypher-and-gql/the-power-of-business-leader-networks/).
+
+## What it does
+
+Maps professional relationships between business leaders so sales and marketing teams can:
+
+- **Find introduction paths** — shortest connection chain to any target leader ("6 degrees" warm intro)
+- **Identify top connectors** — bridge nodes that unlock the largest portions of the network
+- **Target by industry** — all reachable leaders in FinTech, HealthTech, CleanTech, etc.
+- **Explore company networks** — employees, board members, and alumni for any company
+- **Analyse mutual connections** — shared contacts between any two leaders
+
+## Graph Schema
+
+```
+(:BusinessLeader {id, name, title, email, linkedin_url, bio, influence_score})
+  -[:WORKS_AT      {since, current}]->          (:Company)
+  -[:KNOWS         {since, source, strength}]->  (:BusinessLeader)
+  -[:BOARD_MEMBER_OF {since}]->                  (:Company)
+  -[:PREVIOUSLY_WORKED_AT {from, to, title}]->   (:Company)
+
+(:Company {id, name, industry, size, hq_city, website, description})
+(:Industry {name})
+```
+
+## Key Cypher Queries
+
+**Shortest introduction path**
+```cypher
+MATCH path = shortestPath(
+  (source:BusinessLeader {id: $source_id})-[:KNOWS*..6]-(target:BusinessLeader {id: $target_id})
+)
+RETURN nodes(path)
+```
+
+**Extended network within N hops**
+```cypher
+MATCH (source:BusinessLeader {id: $id})-[:KNOWS*1..$hops]-(reachable:BusinessLeader)
+WHERE source <> reachable
+RETURN DISTINCT reachable ORDER BY reachable.influence_score DESC
+```
+
+**Top connectors (bridge nodes)**
+```cypher
+MATCH (l:BusinessLeader)-[:KNOWS]-(other)
+WITH l, count(DISTINCT other) AS degree
+RETURN l.name, degree ORDER BY degree DESC
+```
+
+**B2B industry targeting**
+```cypher
+MATCH (l:BusinessLeader)-[:WORKS_AT {current: true}]->(c:Company {industry: $industry})
+OPTIONAL MATCH (l)-[:KNOWS]-(other)
+WITH l, c, count(DISTINCT other) AS connections
+RETURN l.name, c.name, connections ORDER BY connections DESC
+```
+
+**Mutual connections**
+```cypher
+MATCH (a:BusinessLeader {id: $id})-[:KNOWS]-(mutual)-[:KNOWS]-(b:BusinessLeader {id: $other_id})
+WHERE a <> b AND mutual <> a AND mutual <> b
+RETURN DISTINCT mutual
+```
+
+## Setup
+
+### 1. Install & start Neo4j
+
+Download Neo4j Community Edition from https://neo4j.com/download/
+Default credentials: `neo4j` / `password` (change via Neo4j Browser on first login)
+
+### 2. Configure environment
+
+```bash
+export NEO4J_URL=http://localhost:7474
+export NEO4J_USERNAME=neo4j
+export NEO4J_PASSWORD=your_password
+```
+
+### 3. Install Ruby dependencies
+
+```bash
+bundle install
+```
+
+### 4. Seed the graph
+
+```bash
+rake db:seed
+```
+
+This loads 20 business leaders across 8 companies (FinTech, Data & AI, Cybersecurity, HealthTech, Real Estate, SaaS/ERP, CleanTech, Media), 38 KNOWS relationships, 7 board seats, and 7 work-history entries.
+
+### 5. Start the server
+
+```bash
+rails server
+```
+
+Open http://localhost:3000
+
+## Rake Tasks
+
+```bash
+rake neo4j:status          # Check connection and print graph stats
+rake neo4j:top_connectors  # Print top-connected leaders to stdout
+rake neo4j:reset           # Clear all graph data (prompts for confirmation)
+rake CYPHER='...' neo4j:query  # Run a raw Cypher query
+```
+
+## Architecture
+
+| File | Purpose |
+|------|---------|
+| `lib/neo4j/client.rb` | Raw HTTP client for Neo4j's transactional Cypher endpoint |
+| `config/initializers/neo4j.rb` | Boot-time connection + schema/index creation |
+| `app/models/business_leader.rb` | Graph ORM for `:BusinessLeader` nodes + path queries |
+| `app/models/company.rb` | Graph ORM for `:Company` nodes |
+| `app/controllers/business_leaders_controller.rb` | Profile, network, path, mutual views |
+| `app/controllers/companies_controller.rb` | Company directory and detail |
+| `app/controllers/network_controller.rb` | Dashboard, top connectors, industry targeting |
+| `db/seeds.rb` | Sample graph with 20 leaders, 8 companies, 38 connections |
+| `lib/tasks/neo4j.rake` | Operational rake tasks |

app/controllers/business_leaders_controller.rb

@@ -0,0 +1,56 @@
+class BusinessLeadersController < ApplicationController
+  # GET /business_leaders
+  def index
+    @leaders = if params[:q].present?
+                 BusinessLeader.search(params[:q])
+               else
+                 BusinessLeader.all
+               end
+  end
+
+  # GET /business_leaders/:id
+  def show
+    @leader = BusinessLeader.find(params[:id])
+    return render :not_found unless @leader
+
+    @connections     = @leader.connections
+    @current_company = @leader.current_company
+    @board_seats     = @leader.board_seats
+    @work_history    = @leader.work_history
+  end
+
+  # GET /business_leaders/:id/network
+  # Returns the extended network up to N hops for B2B targeting
+  def network
+    @leader = BusinessLeader.find(params[:id])
+    return render :not_found unless @leader
+
+    hops = (params[:hops] || 2).to_i.clamp(1, 3)
+    @network_leaders = @leader.network_within(hops)
+    @hops = hops
+  end
+
+  # GET /business_leaders/:id/path?target_id=…
+  # Introduction chain: who can introduce me to the target leader?
+  def path
+    @leader = BusinessLeader.find(params[:id])
+    return render :not_found unless @leader
+
+    @target = BusinessLeader.find(params[:target_id])
+    return render :not_found unless @target
+
+    @path    = @leader.introduction_path_to(@target.id)
+    @degrees = @path.length - 1
+  end
+
+  # GET /business_leaders/:id/mutual?other_id=…
+  def mutual
+    @leader = BusinessLeader.find(params[:id])
+    return render :not_found unless @leader
+
+    @other   = BusinessLeader.find(params[:other_id])
+    return render :not_found unless @other
+
+    @mutual = @leader.mutual_connections_with(@other.id)
+  end
+end

app/controllers/companies_controller.rb

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+class CompaniesController < ApplicationController
+  # GET /companies
+  def index
+    @companies  = if params[:industry].present?
+                    Company.by_industry(params[:industry])
+                  else
+                    Company.all
+                  end
+    @industries = Company.industries
+  end
+
+  # GET /companies/:id
+  def show
+    @company      = Company.find(params[:id])
+    return render :not_found unless @company
+
+    @employees    = @company.current_employees
+    @board        = @company.board_members
+    @alumni       = @company.alumni
+  end
+end

app/controllers/network_controller.rb

@@ -0,0 +1,67 @@
+# High-level B2B intelligence queries that span the whole graph
+class NetworkController < ApplicationController
+  # GET /network
+  # Dashboard with top influencers and recent stats
+  def index
+    @top_leaders = NEO4J.query(<<~CYPHER)
+      MATCH (l:BusinessLeader)
+      OPTIONAL MATCH (l)-[:WORKS_AT {current: true}]->(c:Company)
+      RETURN l.id AS id, l.name AS name, l.title AS title,
+             c.name AS company_name, l.influence_score AS influence_score
+      ORDER BY l.influence_score DESC
+      LIMIT 10
+    CYPHER
+
+    @stats = {
+      leaders:       NEO4J.query('MATCH (l:BusinessLeader) RETURN count(l) AS n').first&.fetch('n', 0),
+      companies:     NEO4J.query('MATCH (c:Company) RETURN count(c) AS n').first&.fetch('n', 0),
+      connections:   NEO4J.query('MATCH ()-[r:KNOWS]->() RETURN count(r) AS n').first&.fetch('n', 0),
+      board_seats:   NEO4J.query('MATCH ()-[r:BOARD_MEMBER_OF]->() RETURN count(r) AS n').first&.fetch('n', 0),
+    }
+
+    @industries = NEO4J.query(<<~CYPHER)
+      MATCH (c:Company)<-[:WORKS_AT {current: true}]-(l:BusinessLeader)
+      RETURN c.industry AS industry, count(DISTINCT l) AS leader_count
+      ORDER BY leader_count DESC
+    CYPHER
+  end
+
+  # GET /network/top_connectors
+  # Business leaders with the most connections — the key "bridge nodes" for
+  # reaching new prospects (the warm-intro strategy described in the article)
+  def top_connectors
+    @connectors = NEO4J.query(<<~CYPHER)
+      MATCH (l:BusinessLeader)-[:KNOWS]-(other)
+      WITH l, count(DISTINCT other) AS degree
+      OPTIONAL MATCH (l)-[:WORKS_AT {current: true}]->(c:Company)
+      RETURN l.id AS id, l.name AS name, l.title AS title,
+             c.name AS company_name, l.influence_score AS influence_score,
+             degree
+      ORDER BY degree DESC
+      LIMIT 20
+    CYPHER
+  end
+
+  # GET /network/by_industry?industry=FinTech
+  # All leaders in a given industry with their connection counts —
+  # the primary B2B targeting view
+  def by_industry
+    @industry = params[:industry]
+    return redirect_to network_path unless @industry.present?
+
+    @leaders = NEO4J.query(<<~CYPHER, industry: @industry)
+      MATCH (l:BusinessLeader)-[:WORKS_AT {current: true}]->(c:Company {industry: $industry})
+      OPTIONAL MATCH (l)-[:KNOWS]-(other)
+      WITH l, c, count(DISTINCT other) AS connections
+      RETURN l.id AS id, l.name AS name, l.title AS title,
+             c.name AS company_name, l.influence_score AS influence_score,
+             connections
+      ORDER BY connections DESC, l.influence_score DESC
+    CYPHER
+
+    @industries = NEO4J.query(<<~CYPHER)
+      MATCH (c:Company)
+      RETURN DISTINCT c.industry AS industry ORDER BY industry
+    CYPHER
+  end
+end