How should a business modernize legacy systems?

Legacy modernisation works best when it starts with the business constraint, not with a blanket rebuild.

Direct answer

A business should modernize legacy systems by identifying which part of the system creates the most commercial drag, separating risky refactors from unrelated roadmap work, sequencing changes around continuity, and improving release safety before broad transformation.

The risk

Large modernisation programs become expensive when they try to fix everything at once.

The focused alternative

Balazs's Tech Velocity case study shows a narrower path: identify the legacy data flow that slowed delivery, isolate it, and improve velocity without pausing the business.

What to protect

Modernisation should protect customer experience, delivery momentum, and team confidence while removing the highest-impact constraint.