Is it still worth running a legacy commerce system?

TL;DR

• Running legacy systems puts a heavy burden on IT teams due to high maintenance costs, technical debt, and long time-to-market.
• Customizations and new requirements often need to be individually developed rather than simply configured.
• IT departments are overwhelmed by business requests and reduced to operational implementers.
• Modern requirements like omnichannel, automation, or self-service are difficult to implement.
• A gradual transition using API layers, orchestration, and the Strangler Pattern can ease the burden and open up new possibilities.
• Modern commerce architectures provide more control, reduce custom code, and turn IT back into an enabler.

The hidden costs of the status quo

“Never change a running system” might sound pragmatic, but it’s costly. Operating a legacy system comes with visible costs like maintenance, licensing, and hosting - but the more significant burden lies in the hidden effort, especially for IT teams:

• Customizations take an unreasonable amount of time because processes are deeply embedded in the code
• Updates are risky and require extensive regression testing
• New requirements demand custom code instead of configuration via a UI
• Business teams depend on IT instead of acting independently

There’s also the everyday frustration: IT teams are constantly fielding urgent requests from business units - regardless of whether the technical foundation is even suitable. This leads to recurring rework, prioritization conflicts, and chronic overload.

The result? Long time-to-market, stalled innovation, and reduced competitiveness - turning IT from an enabler into a bottleneck.

New demands, old architecture

Modern commerce processes are dynamic. Customers expect seamless omnichannel experiences, real-time information, and fast response times. Companies want to be agile, integrate new services, and respond quickly to market changes. Legacy systems run into structural limitations:

• Rigid data models slow down process innovation
• Monolithic architectures hinder integration and the use of modern APIs
• Lack of modularity increases complexity in DevOps and QA

Often, it’s not specific features that are missing - it’s the inability to adapt. IT departments become “firefighting teams” rather than strategic architects of digital transformation.

When the pain becomes real

IT teams experience these limitations firsthand in their day-to-day operations:

• Even minor changes require resources for development, testing, and deployment
• Release cycles are prolonged due to regression testing and technical dependencies
• Maintenance costs rise due to outdated frameworks and lack of know-how
• Strategic initiatives like self-service, automation, or event-driven architecture fail due to technical constraints

At the same time, critical projects are often put on hold because the team is stuck handling granular requests that business departments should be able to manage themselves.

At this point, running the old system doesn’t just become expensive - it actively blocks innovation.

What are the options?

A full platform replacement is rarely the answer - and risky from an IT perspective. A more effective approach is a gradual, controlled transition:

• Strangler Pattern: Develop new functionality as standalone services outside the legacy system
• Implement API layers: Decouple data and processes and expose them through modern interfaces
• Introduce orchestration: Extract business logic from the core system and manage it in a centralized, controllable process layer

This allows IT to leverage modern technology while ensuring business continuity.

Looking ahead: More control, less custom code

Many companies fall into the trap of focusing solely on composability. The idea of being able to combine anything with anything sounds appealing - but in practice, it often leads to a new problem: the Custom Code Trap.

When you pursue pure composability without centralized process control, you’re simply shifting complexity to another technical layer. Instead of real flexibility, you end up with a patchwork of services tied together by custom code - bringing all the usual downsides: high maintenance effort, developer dependency, and lack of transparency.

What’s missing is intelligent orchestration: a central layer where processes can be configured and controlled - rather than reinvented every time.

Modern commerce architectures are built around openness, modularity, and process intelligence. Instead of repeatedly writing custom code, they enable:

• Reusable services
• Configurable process logic through no-/low-code
• Centralized control and monitoring of business processes

This means IT teams regain time, quality, and control - and can focus again on what truly matters strategically.

Conclusion: Legacy is no place to stay

Continuing to run a legacy system may seem comfortable for now. But those who fail to modernize today will pay the price tomorrow - with rigid processes, inefficient IT, and missed opportunities.

The good news? There’s a way to break free from the legacy trap - one step at a time. And it usually starts with a simple question:

What would it mean for our IT team if it no longer had to dive into the code for every business rule?