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API Development & Integration

Connect your systems, automate data flow, and build custom APIs that power your digital ecosystem.

What is API development and integration?

API development is building the connections that let your software systems share data — between your own apps, with vendor platforms (Salesforce, Stripe, HubSpot, QuickBooks), and with partners. A well-designed API removes manual exports, eliminates duplicate data entry, and makes the rest of your stack composable instead of siloed.

Custom API development: REST, GraphQL, and WebSocket APIs designed to your use case, with versioning, authentication, rate limiting, and documentation built in from day one.

Third-party integrations: We handle the unglamorous work that breaks in-house projects — OAuth flows, rate limits, retry logic, data-shape mismatches, and webhook delivery — so the integration keeps running after launch.

API development and system integration architecture diagram

What kinds of API and integration work do we cover?

Nine focus areas from custom REST APIs to legacy integration and analytics

Custom API Development

Build RESTful APIs, GraphQL endpoints, and real-time APIs designed specifically for your application needs.

Third-Party Integrations

Connect with CRMs, payment processors, marketing tools, accounting software, and more.

Cloud API Integration

Integrate with AWS, Google Cloud, Azure services for enhanced functionality and scalability.

Database API Design

Design efficient database APIs with optimized queries, caching, and data transformation.

API Security & Authentication

Implement OAuth 2.0, JWT, API keys, and enterprise-grade security protocols.

Legacy System Integration

Modernize legacy systems by creating APIs that bridge old and new technologies.

Webhook Development

Build real-time webhook systems for instant data synchronization and event-driven architecture.

API Documentation

Create comprehensive API documentation with Swagger/OpenAPI for developers.

API Analytics & Monitoring

Track API usage, performance metrics, and health monitoring for optimal operation.

REST vs GraphQL vs Webhooks vs iPaaS: which API pattern fits your project?

Most integration projects pick one (or a mix) of four patterns. REST is the safe default; GraphQL pays off when clients need flexible shapes; webhooks shine for real-time events; iPaaS tools (Workato, Boomi, MuleSoft) are fastest when you are wiring up well-known SaaS apps. The table below shows the tradeoffs.

PatternComplexityCostBest use caseMaintenance
RESTLow$ build; $ opsPublic APIs, CRUD over resources, partner integrationsLow; versioned endpoints stay stable
GraphQLMedium$$ build; $$ opsFrontends needing flexible shapes; aggregating multiple data sourcesMedium; schema evolution needs discipline
WebhooksLow–Medium$ build; $ ops + queueReal-time events, system-to-system notificationsMedium; needs retry/idempotency design
iPaaS (Workato, Boomi, MuleSoft)Low to set up; medium to govern$$$ subscription; faster buildStitching well-known SaaS apps quickly; non-engineer ownershipLow day-to-day; vendor lock-in is the risk

Complexity and cost ratings reflect Verlua engagement experience. Most production stacks combine REST + webhooks; iPaaS is added when speed matters more than ownership.

Why invest in custom APIs instead of point-to-point integrations?

Four operating advantages well-designed APIs unlock

Increased Efficiency

Automate data exchange between systems, eliminating manual work and reducing errors.

Scalability

Build systems that grow with your business without costly rewrites or migrations.

Cost Savings

Reduce integration costs and maintenance overhead with standardized APIs.

Ecosystem Growth

Enable partners and developers to build on your platform, expanding your reach.

Which API technologies and standards do we work with?

A mainstream stack chosen for long-term maintainability

API Standards

  • REST
  • GraphQL
  • SOAP
  • WebSocket

Authentication

  • OAuth 2.0
  • JWT
  • API Keys
  • SAML

Platforms

  • Node.js
  • Python
  • Go
  • Java

Documentation

  • Swagger
  • Postman
  • OpenAPI
  • Redoc

What does an API and integration project look like in practice?

Six common patterns we ship for mid-market clients

E-commerce Integration

Connect online stores with inventory management, payment gateways, shipping providers, and accounting systems for smooth operations.

CRM & Marketing Automation

Sync customer data between your CRM, email marketing platform, and analytics tools for unified customer insights.

Financial Data Sync

Integrate accounting software with banking systems, payment processors, and financial reporting tools.

IoT & Device Integration

Connect IoT devices and sensors to central systems for real-time monitoring and control.

Multi-Platform Data Sync

Keep data synchronized across web, mobile, and desktop applications in real-time.

Partner & Vendor Integration

Build secure APIs for B2B partners to access your data and services programmatically.

What does Verlua's API development process look like?

Six stages from requirements to ongoing support

1

Requirements & Planning

Analyze your systems, define integration requirements, and create a detailed API specification.

2

API Design

Design the API architecture, endpoints, data models, and authentication strategy.

3

Development

Build the API with clean code, comprehensive error handling, and security measures.

4

Integration & Testing

Connect with target systems and perform thorough testing for reliability and performance.

5

Documentation & Deployment

Create developer documentation and deploy to production with monitoring setup.

6

Ongoing Support

Provide maintenance, updates, and support to ensure continuous optimal operation.

API development & integration FAQ

Buyer questions we hear most often during scoping calls

What types of APIs do you develop?

We develop various API types including REST APIs, GraphQL endpoints, SOAP web services, and real-time WebSocket APIs. Our expertise covers public APIs for third-party access, internal APIs for system communication, and partner APIs for B2B integrations.

How do you ensure API security?

We implement comprehensive security measures including OAuth 2.0 / JWT authentication, API key management, rate limiting, request validation, HTTPS/TLS encryption, and input sanitization. All APIs follow OWASP security best practices.

Can you integrate with legacy systems?

Yes, we specialize in connecting modern applications with legacy systems. We use adapters, middleware, and API gateways to bridge the gap between old and new technologies without disrupting existing operations.

What third-party platforms do you integrate with?

We integrate with virtually any platform that offers API access, including Salesforce, HubSpot, Stripe, PayPal, Shopify, QuickBooks, Google Workspace, Microsoft 365, AWS services, social media platforms, and custom enterprise systems.

How do you handle API versioning and maintenance?

We follow semantic versioning practices and implement backward-compatible changes when possible. Our maintenance includes monitoring, documentation updates, deprecation notices, and smooth migration paths for breaking changes.

How much does a custom API project cost, and how long does it take?

A focused integration (one third-party platform, well-documented) typically runs $8K–$20K and 3–5 weeks. A custom REST API with auth, docs, and a moderate data model is more like $20K–$60K and 6–10 weeks. iPaaS-led builds (Workato, Boomi, MuleSoft) trade higher subscription cost for faster delivery. We confirm the band after a one-call discovery.

Custom API build vs an iPaaS tool like Workato or MuleSoft: when does each make sense?

Use iPaaS when you are wiring together popular SaaS apps and the team owning it is non-engineering — speed-to-launch is the priority. Build custom when the integration is core to your product, when you need fine-grained control over data shape or latency, or when subscription cost at scale would exceed the build cost. Many clients run a mix: iPaaS for back-office plumbing, custom APIs for product surfaces.

What happens after launch — do we own the API or do you?

You own it. We hand over the code in your Git repo, deployment configuration in your cloud account, and an operations runbook covering rotation, monitoring, and on-call. We offer optional maintenance retainers, but they are not required to keep the system running.

Ready to Connect Your Systems?

Let's build custom APIs and integrations that streamline your operations and unlock new capabilities.