API & Integrations
API Integration Services That Connect Your Systems
QASTCO builds API integrations that stop your team copying data between systems. We connect CRMs, ERPs, payment gateways, and marketing platforms into a single automated workflow.
We design REST and GraphQL APIs, write technical documentation, and build monitoring dashboards. If an endpoint fails at 3am, our alerting catches it before you notice.
Get in Touch- REST and GraphQL API development
- Payment gateway integrations (Stripe, PayPal, GoCardless)
- CRM and ERP connectivity (Salesforce, HubSpot, SAP)
- Data migration and transformation pipelines
- Webhook configuration and event-driven architecture
- Uptime monitoring with real-time alerting
API Development and Integration Deliverables
Every integration comes with documentation, monitoring, and error handling built in.
REST & GraphQL APIs
Custom endpoints with versioning, rate limiting, and OpenAPI documentation your team can reference.
Payment Gateways
Stripe, PayPal, GoCardless, and Adyen. PCI-compliant integration with webhook reconciliation.
CRM & ERP Integration
Bi-directional sync between Salesforce, HubSpot, Dynamics 365, and your internal databases.
Data Migration
ETL pipelines that move, clean, and map data between legacy systems and modern platforms.
Webhooks & Events
Event-driven architecture with retry logic, dead-letter queues, and real-time processing.
Monitoring & Alerts
Dashboards tracking latency, error rates, and throughput. Slack and email alerts on anomalies.
Our API Integration Process
We map your data flows, build the connections, and monitor them long-term.
Audit & Map
We document every system, endpoint, and data field. You get a visual integration map before work starts.
Build & Test
Sandbox testing with real data samples. We validate every edge case before touching production.
Deploy & Monitor
Live deployment with rollback plans. Ongoing monitoring dashboards track performance 24/7.
API Integration FAQs
An API (Application Programming Interface) allows your software systems to talk to each other automatically. For example, connecting your website to your CRM so new enquiries appear instantly, or syncing your inventory system with your online shop. It removes manual data entry and reduces errors.
We integrate with CRMs (HubSpot, Salesforce), payment gateways (Stripe, PayPal), accounting tools (Xero, QuickBooks), shipping providers, email platforms, and most SaaS tools that offer an API. If the system has an API, we can connect it.
We use OAuth 2.0 authentication, encrypted API keys stored in environment variables, HTTPS for all data transfer, and rate limiting to prevent abuse. All integrations are tested against OWASP security standards before going live.
REST APIs use fixed endpoints that return predefined data structures, which suits most standard integrations. GraphQL lets clients request exactly the data they need in a single query, which is more efficient for complex or mobile applications. We recommend the approach that fits your data patterns.
We set up automated health checks, error logging, and uptime monitoring. If an endpoint fails or response times spike, we get alerted immediately. We also track usage metrics so you can see how your integrations perform over time.
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