HubSpot Architecture Variants

Overview

Three validated architecture patterns for HubSpot CRM integrations at different scales, from embedded client to dedicated API gateway.

Prerequisites

• Understanding of team size and daily API call volume
• Knowledge of deployment infrastructure
• Clear sync requirements (real-time vs batch)

Instructions

Variant A: Embedded Client (Simple)

Best for: MVPs, small teams, < 10K contacts, < 50K API calls/day

your-app/
├── src/
│   ├── hubspot/
│   │   ├── client.ts       # @hubspot/api-client singleton
│   │   └── contacts.ts     # Direct CRM operations
│   ├── routes/
│   │   └── api.ts           # API routes that call HubSpot directly
│   └── index.ts

// Direct integration in route handlers
import * as hubspot from '@hubspot/api-client';

const client = new hubspot.Client({
  accessToken: process.env.HUBSPOT_ACCESS_TOKEN!,
  numberOfApiCallRetries: 3,
});

app.get('/api/contacts', async (req, res) => {
  const page = await client.crm.contacts.basicApi.getPage(
    20, req.query.after as string, ['email', 'firstname', 'lastname']
  );
  res.json(page);
});

app.post('/api/contacts', async (req, res) => {
  const contact = await client.crm.contacts.basicApi.create({
    properties: req.body,
    associations: [],
  });
  res.status(201).json(contact);
});

Pros: Fast to build, simple to understand, one deployment Cons: No fault isolation, HubSpot latency in user request path

---

Variant B: Service Layer with Async Queue

Best for: Growing teams, 10K-100K contacts, 50K-300K API calls/day

your-app/
├── src/
│   ├── services/
│   │   └── hubspot/
│   │       ├── client.ts       # Singleton with circuit breaker
│   │       ├── contact.ts      # Business logic layer
│   │       ├── deal.ts
│   │       └── sync.ts         # Background sync
│   ├── queue/
│   │   └── hubspot-worker.ts   # Process async operations
│   ├── cache/
│   │   └── hubspot-cache.ts    # Redis cache layer
│   ├── routes/
│   └── index.ts

// Service layer abstracts HubSpot from route handlers
class ContactService {
  private client = getHubSpotClient();
  private cache: Redis;
  private queue: BullQueue;

  async getContact(id: string): Promise<Contact> {
    // Check cache first
    const cached = await this.cache.get(`contact:${id}`);
    if (cached) return JSON.parse(cached);

    // Fetch from HubSpot
    const contact = await this.client.crm.contacts.basicApi.getById(
      id, ['email', 'firstname', 'lastname', 'lifecyclestage']
    );

    // Cache for 5 minutes
    await this.cache.setex(`contact:${id}`, 300, JSON.stringify(contact));
    return contact;
  }

  async createContact(data: CreateContactInput): Promise<{ jobId: string }> {
    // Enqueue for async processing (fast API response)
    const job = await this.queue.add('create-contact', data);
    return { jobId: job.id };
  }
}

// Background worker
queue.process('create-contact', async (job) => {
  const contact = await client.crm.contacts.basicApi.create({
    properties: job.data,
    associations: [],
  });
  // Invalidate cache, send notification, etc.
  await cache.del(`contacts:list`);
  return contact;
});

Pros: Fault isolation, fast API responses, caching, background processing Cons: More complexity, Redis dependency, two process types

---

Variant C: Dedicated HubSpot Gateway

Best for: Enterprise, 100K+ contacts, multiple services needing CRM access

hubspot-gateway/               # Standalone service
├── src/
│   ├── api/
│   │   ├── grpc/              # Internal gRPC API
│   │   │   └── hubspot.proto
│   │   └── rest/              # REST API (optional)
│   ├── domain/
│   │   ├── contacts.ts        # Domain logic
│   │   ├── deals.ts
│   │   └── sync.ts
│   ├── infrastructure/
│   │   ├── hubspot-client.ts  # SDK wrapper
│   │   ├── rate-limiter.ts    # Centralized rate limiting
│   │   ├── cache.ts           # Redis cache
│   │   └── circuit-breaker.ts
│   └── index.ts
├── k8s/
│   ├── deployment.yaml
│   └── hpa.yaml

other-services/
├── order-service/      # Calls hubspot-gateway
├── marketing-service/  # Calls hubspot-gateway
└── analytics-service/  # Calls hubspot-gateway

// All HubSpot access goes through the gateway
// Gateway handles rate limiting, caching, and circuit breaking

// Centralized rate limiter ensures all services share the 10 req/sec limit
class CentralizedRateLimiter {
  private redis: Redis;
  private maxPerSecond = 8; // leave headroom

  async acquire(): Promise<void> {
    const key = `hubspot:ratelimit:${Math.floor(Date.now() / 1000)}`;
    const count = await this.redis.incr(key);
    await this.redis.expire(key, 2);

    if (count > this.maxPerSecond) {
      throw new Error('HubSpot rate limit -- waiting');
    }
  }
}

Pros: Single point of rate limiting, all services share cache, independent scaling Cons: Network hop, operational complexity, gRPC/REST contract management

---

Decision Matrix

Factor	Embedded	Service Layer	Gateway
Team size	1-3	3-15	15+
Contacts	< 10K	10K-100K	100K+
Services using CRM	1	1-2	3+
Sync model	Synchronous	Async queue	Event-driven
Cache	In-memory	Redis	Redis + CDN
Rate limit mgmt	SDK built-in	App-level	Centralized
Fault isolation	None	Partial	Full
Time to build	Days	1-2 weeks	3-4 weeks

Migration Path

Embedded → Service Layer:
  1. Extract HubSpot client to services/hubspot/
  2. Add Redis cache layer
  3. Move writes to background queue

Service Layer → Gateway:
  1. Extract to standalone service
  2. Define gRPC/REST contract
  3. Add centralized rate limiter
  4. Migrate services one at a time

Output

• Three validated architecture patterns with code examples
• Decision matrix for choosing the right pattern
• Migration path from simpler to more complex architectures

Error Handling

Issue	Cause	Solution
Over-engineering	Wrong variant choice	Start with Embedded, evolve
Rate limit shared	Multiple services hitting HubSpot	Move to Gateway pattern
Cache inconsistency	No invalidation strategy	Invalidate on webhook events
Gateway single point of failure	No redundancy	Run multiple replicas + HPA

Resources

• HubSpot API Client GitHub
• HubSpot API Usage Guidelines
• Monolith First (Martin Fowler)

Next Steps

For common anti-patterns, see

hubspot-known-pitfalls

.