Build vs Buy: The Integration Decision Framework

The integration question every business faces

You need your tools to talk to each other. Sales data from Stripe should flow into your CRM. Support tickets should create Slack notifications. New leads should trigger email sequences.

The question is: do you build these integrations yourself, or do you use a platform like Zapier or Make?

The answer matters because the wrong choice costs real money. Build when you should buy, and you'll waste months of engineering time. Buy when you should build, and you'll hit limitations that throttle your business.

Here's how to make the right call.

The default answer for most businesses

Let's start with the uncomfortable truth: for most businesses, most of the time, the answer is "buy" not "build."

Integration platforms like Zapier, Make (formerly Integromat), and n8n exist for good reason. They handle the messy details—authentication, error handling, rate limiting, API version changes—so you don't have to.

For standard workflows (form submission to CRM, new customer to email list, payment to accounting system), these platforms work brilliantly. They're faster to set up, require no code, and someone else maintains them when APIs change.

Use an integration platform when:

• •The integration connects popular SaaS tools with standard workflows
• •Speed to market matters more than customisation
• •You lack dedicated engineering resources
• •The data volume is reasonable (under 100k operations monthly for most platforms)
• •You need flexibility to modify workflows without code changes
• •The integration is nice-to-have rather than business-critical

When custom integrations make sense

Some scenarios genuinely require custom development.

Build a custom integration when:

The integration is core to your product value. If the integration is what customers pay you for, don't rely on third-party platforms. You need complete control, customisation, and reliability.

Example: A booking platform that syncs with property management systems. This is the product, not a convenience feature. Build it.

You need deep customisation. Integration platforms offer configurability within limits. If you need complex data transformation, custom business logic, or unusual workflows, those limits become problems.

Example: Syncing inventory across multiple systems with complex reconciliation rules. Platform limitations will frustrate you quickly.

Performance requirements exceed platform capabilities. Most integration platforms are designed for moderate usage. High-frequency syncs, large data volumes, or sub-second latency requirements push beyond their sweet spot.

Example: Real-time inventory updates across 50 locations with thousands of SKUs. You'll hit rate limits and delays with platforms.

You're integrating internal systems. If you're connecting your own databases and services, integration platforms add unnecessary complexity. Direct API calls are simpler.

Example: Your React frontend needs to query your Node.js backend. This doesn't need Zapier in the middle.

The total cost of ownership favours building. Once your usage scales sufficiently, platform pricing can exceed the cost of building and maintaining custom integrations.

Example: Processing 500k operations monthly on Zapier costs £400+/month. A custom solution might cost £5k to build and £500/year to maintain. Break-even is month 13.

The hidden costs of building

Custom integrations seem cheaper until you account for the full costs.

Initial development time. What seems like a weekend project often takes weeks. OAuth flows, error handling, logging, monitoring—there's more to it than the happy path.

Budget 3-5x your initial estimate. Seriously.

Ongoing maintenance. APIs change. Rate limits adjust. Authentication methods evolve. Someone needs to monitor and maintain your integrations.

This is often 20-30% of initial development time, annually, forever.

Opportunity cost. Engineering time spent building integrations is time not spent on your core product. Is this the best use of your scarcest resource?

Reliability burden. When your custom integration breaks at 2am, it's your problem. With platforms, it's their problem.

Knowledge concentration. If one developer builds an integration and leaves, that knowledge walks out the door. Platforms are self-documenting.

The hybrid approach

The binary framing of build versus buy is often wrong. The best solution is frequently "both."

Use platforms for the simple stuff. Form to CRM, payment to accounting, new user to email list. Let Zapier handle these.

Build custom for core integrations. The integrations that differentiate your business, require deep customisation, or handle sensitive data—build these properly.

Start with platforms, graduate to custom. Begin with Zapier to validate the workflow. Once it proves valuable and hits limitations, migrate to custom.

Example: We helped a client launch with Zapier connecting their booking system to customer emails. Once they scaled to 10k bookings monthly, we built a custom solution. They validated demand before investing in custom code.

The evaluation framework

Here's a practical decision framework:

Step 1: Define integration requirements

• •What systems are you connecting?
• •What data needs to flow where?
• •How frequently? What volume?
• •What's the acceptable delay?
• •What happens when it fails?
• •Who maintains this?

Step 2: Calculate platform feasibility

• •Does the platform support both systems?
• •Can it handle your data volume within pricing tiers?
• •Do built-in transformations cover your logic?
• •Is reliability acceptable for your use case?

Step 3: Estimate custom development costs

• •Engineering time to build (multiply estimate by 3)
• •Ongoing maintenance burden
• •Opportunity cost of engineering time
• •Infrastructure costs

Step 4: Compare total cost of ownership

Platform cost over 24 months vs. custom development cost plus 24 months of maintenance.

Step 5: Weight non-financial factors

• •Time to market urgency
• •Control and customisation needs
• •Reliability requirements
• •Strategic importance
• •Team capabilities

Common scenarios and recommendations

Scenario: Startup connecting standard SaaS tools

Recommendation: Use integration platforms. Your priority is validating product-market fit, not building infrastructure.

Scenario: Established business with complex workflows

Recommendation: Hybrid. Platforms for simple integrations, custom for core business logic.

Scenario: Product company where integration IS the product

Recommendation: Build custom. Your customers pay you for this capability. Own it completely.

Scenario: High-volume data processing

Recommendation: Build custom. Platform costs and limitations make this uneconomical at scale.

Scenario: Connecting internal microservices

Recommendation: Build custom. Integration platforms add unnecessary complexity and cost.

Scenario: Proof of concept or experiment

Recommendation: Use platforms. Validate the concept before investing in custom development.

The technology choices for custom integrations

If you decide to build custom, you have options.

Serverless functions (AWS Lambda, Google Cloud Functions): Good for event-driven integrations. Pay per use, scales automatically, minimal infrastructure.

Background job processors (Sidekiq, Bull, Celery): Better for scheduled syncs, batch processing, complex workflows. More infrastructure but more control.

API orchestration frameworks (n8n self-hosted, Airflow): Middle ground between no-code platforms and fully custom. Self-hosted gives you control with some platform benefits.

Direct API integration in application code: Simplest for straightforward integrations tightly coupled to your application logic.

Choose based on your integration characteristics and team expertise.

Risk mitigation strategies

Whether you build or buy, mitigate these risks:

For platforms:

• •Monitor usage to avoid surprise cost escalations
• •Have migration plans for critical integrations
• •Don't build your core product on top of platforms
• •Use platforms that export workflow configurations

For custom:

• •Document thoroughly from the start
• •Build with monitoring and alerting from day one
• •Plan for API versioning and backward compatibility
• •Have runbooks for common failure scenarios
• •Ensure knowledge distribution across team

Real-world examples

Success with platforms: E-commerce company connected Shopify to Xero accounting, Mailchimp, and Google Sheets for reporting. Total monthly cost: £50. Alternative custom build: £15k minimum. Clear winner: platform.

Success with custom: SaaS platform built deep Salesforce integration as a core product feature. Customers pay £500/month extra for this capability. Platform limitations would have been a non-starter. Clear winner: custom.

Hybrid success: Hospitality business uses Zapier for 15+ simple integrations (booking to email, payment to accounting, etc.) costing £100/month. Built custom integration for their core reservation system connecting to property management. Best of both: platform for commodity, custom for differentiation.

The decision timeline

Immediate needs (next 2 weeks): Use platforms unless you have custom code ready to go.

Short term (1-3 months): Platforms are usually right. Even if you'll eventually build custom, platforms validate the workflow faster.

Medium term (3-12 months): Evaluate whether initial platform choice is sustainable. If hitting limits, plan custom migration.

Long term (12+ months): Strategic integrations should probably be custom. You've validated demand and understand requirements fully.

When to reconsider your choice

Your decision isn't permanent. Reconsider when:

Platform to custom: - Usage costs exceed custom development break-even - You're hitting platform limitations frequently - The integration becomes business-critical - You need customisation the platform can't support

Custom to platform: - Maintenance burden exceeds expectations - The integration isn't as strategic as anticipated - Team bandwidth for maintenance is limited - Platform capabilities have expanded to cover your needs

Getting help with the decision

Sometimes you need external perspective.

Consult technical advisors when: - The integration is business-critical and you're uncertain - Cost projections vary wildly between options - Your team lacks experience building integrations - You're committing significant resources either way

Red flags in advice: - "Always build custom" (usually from developers who want to build things) - "Always use platforms" (usually from consultants who get platform affiliate fees) - Failure to discuss total cost of ownership - Ignoring your specific context and constraints

Good advisors ask about your business model, team capabilities, timelines, and risk tolerance before recommending an approach.

The bottom line

There's no universal answer to build versus buy for integrations. The right choice depends on your specific context.

Most businesses should default to integration platforms for standard workflows and save custom development for integrations that differentiate their business.

The key is being honest about requirements, costs, and capabilities. Don't build custom to satisfy engineering egos. Don't use platforms beyond their limitations because you're afraid of code.

Evaluate systematically, choose deliberately, and be willing to change your mind as circumstances evolve.

Your integration strategy should serve your business, not the other way around.

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Need help deciding?

At LogicLeap, we've built dozens of custom integrations and implemented hundreds using platforms. We can help you evaluate your specific situation and make the right choice.

[Get in touch](/contact) for a free consultation on your integration strategy.