Integration Challenges (Legacy Systems & Modern APIs)

Your legacy system works. It handles the core of your business — the orders, the inventory, the customer records. It has worked for 15 or 20 years, and it will probably keep working for another decade if left alone.

The problem is that the rest of the world has moved on. Payment processors now require REST API calls. Your CRM expects real-time webhooks. Your shipping provider sends JSON payloads. Your customers want to log in via an app. And your .NET Framework WebForms system, or your FoxPro application, or your Classic ASP backend speaks none of these languages.

You have two options: rebuild the entire system to support modern integrations (expensive, slow, risky), or build a bridge.

We build bridges.

What Integration Actually Looks Like

A legacy system integration typically involves adding a layer between the old system and the modern world — without touching the core business logic that's been running reliably for years. We call this a middleware layer, though the implementation varies significantly by situation.

For a Classic ASP system that needs to accept Stripe webhooks: we build a lightweight ASP.NET Core receiver that processes the Stripe event and writes it to the database in the format the legacy system already understands. The Classic ASP system never knows Stripe exists. Stripe never knows Classic ASP exists. Both keep doing what they do.

For a FoxPro system that needs to expose data to a web dashboard: we build a REST API layer that reads from the DBF files (or from a synchronized SQL Server copy), formats the data as JSON, and serves it to whatever front end needs it. The FoxPro system keeps running unmodified.

For a .NET Framework WebForms ERP that needs to connect to a modern CRM: we build a synchronization pipeline — either a Windows Service or an Azure Function — that runs on a schedule, reads changed records from the ERP, and pushes them to the CRM via its API. Bidirectional if needed.

Common Scenarios We Handle

Payment processing — Adding Stripe, Square, or PayPal to a legacy system that currently handles payments manually or through an outdated processor.

CRM synchronization — Connecting legacy ERP or custom CRM data to HubSpot, Salesforce, or similar platforms. Usually bidirectional — changes in either system reflect in the other.

Shipping and logistics — Integrating legacy order management with FedEx, UPS, or Australia Post APIs for real-time rate calculation, label generation, and tracking.

Document generation — Building modern PDF or email generation on top of legacy data, replacing aging Crystal Reports or legacy printing workflows.

Authentication modernization — Adding modern SSO, OAuth 2.0, or Azure AD authentication to a system that currently uses bespoke username/password handling, without replacing the underlying system.

Data exposure via API — Wrapping legacy data in a REST or GraphQL API so modern applications, mobile apps, or third-party services can read it.

Webhook ingestion — Building receivers for modern webhook-based services (Stripe, Twilio, GitHub, Shopify) that translate events into formats the legacy system understands.

Why This Approach Works

Integration is often the fastest and lowest-risk path to modernization. You get the modern capability you need — payment processing, real-time sync, web dashboards — without touching the system that's running your business. That system keeps running. Its business logic stays intact. The disruption is minimal.

It also buys you time. A well-designed integration layer can extend the useful life of a legacy system by five to ten years, giving you the space to plan a proper migration on your own timeline, with budget and preparation, rather than under emergency pressure.

Investment

Integration engagements start at $20,000 for straightforward single-service integrations and scale with complexity. Multi-system integrations with bidirectional sync are scoped individually. All engagements begin with a technical assessment to understand your existing architecture before any integration is designed.