The Correct Cloud Approach for Legacy Fat Client Applications

7 days ago
3 min read

Many law firms today still rely on non‑web, fat client applications that have been around for 20+ years—systems like Tabs3, Juris, and others that continue to power billing and financial operations.

Now that “cloud” has become the industry standard, firms are being encouraged to migrate. But before you make that move, it’s critical to recognize a common trap:

Not all “cloud” solutions are actually cloud.

The Trap: Hosting Disguised as Cloud

Some software vendors have chosen not to modernize their technology stack. Instead, they offer a “cloud” version of the same legacy system—simply hosted in their infrastructure.

On the surface, this sounds appealing:

No servers to manage
Access from anywhere
Subscription pricing

But under the hood, nothing has really changed:

The application remains a Windows fat client
The database remains proprietary and closed
The integration model remains limited or nonexistent

Worse, these solutions are often delivered through remote access technologies such as:

Citrix
VMware Horizon (Omnissa)
Other virtual desktop infrastructure (VDI) tools

What you’re really getting is:

A remote desktop session inside a browser—not a true cloud platform.

What You Lose: System Freedom

When you move to a vendor-hosted “cloud” version, you’re not just outsourcing infrastructure—you’re giving up control over your system.

That impacts your firm in several ways:

1. Integration is Severely Limited

APIs have existed for over 20 years. They are the foundation of modern software interoperability.

But in many hosted legacy systems:

APIs are unavailable or restricted
Database access is removed
External tools cannot connect

The result:

Your system becomes a silo.

2. Vendor Lock-In Increases

Once your system is fully hosted by the vendor:

Data access is controlled by them
Migration becomes more complex
Switching systems becomes costly

Your dependency shifts from:

Using softwaretoBeing controlled by it

3. Costs Go Up (Without Real Innovation)

You’re typically paying for:

Hosting infrastructure
Remote access licensing
Ongoing subscription fees

Yet:

The core software hasn’t evolved
User experience may degrade (latency, session timeouts)

What You Should Do Instead

There is a better path—one that gives you cloud benefits without sacrificing control.

✅ Self-Host in Your Own Cloud Tenant

If your firm uses:

Microsoft 365 → You already have Azure
Google Workspace → You already have Google Cloud

This means:

You already own your cloud environment.

The correct architecture is to deploy your legacy application there—not inside your vendor’s black box.

Recommended Architecture

Step 1: Deploy Your Servers

Spin up one or more Windows Servers in Azure or Google Cloud
Optional: separate database server depending on the application

Step 2: Establish Secure Connectivity

Configure an Azure VPN Gateway (or equivalent)
Use entry-level options for smaller firms

Step 3: Keep the Client Local

On each user’s machine:

Install the fat client application
Install a VPN client
Connect directly to your cloud-hosted servers

Step 4: Operate Normally

Users:

Connect via VPN
Launch the application locally
Work as if they are in the office

No remote desktop. No virtualization layer. No artificial constraints.

Self-hosted Tabs3 Cloud Architecture on Azure

Why This Architecture Wins

Category	Self-Hosted Cloud	Vendor-Hosted “Cloud”
Data access from user devices	Controlled, secure direct access	Routed through remote session
Cost	Lower, transparent	Higher (bundled + opaque)
Vendor dependency	0%	100%
Integration flexibility	Full (API / DB access)	Near zero
User experience	Native performance	Clunky remote sessions, laggy performance, and frustrating user experience