Still relying on mainframes from the 70s?
You’re not alone.
Banks, insurance companies, pension funds, and risk assessment firms often depend on core systems built 40–50 years ago. These systems—originally designed for stability and performance—still power mission-critical functions including ledgers, bookkeeping, risk calculations, and long-term financial products. But they’re increasingly becoming a liability.
Legacy technology makes it harder to meet today’s demands. Regulatory pressure, fast-changing markets, rising security threats, and client expectations for digital services. Even thinking about modernization can feel overwhelming. But the cost of doing nothing is even greater.
Financial costs that
still work but
can't be touched
Many financial institutions have developed complex algorithms in RPG, EGL or COBOL, used to assess credit risk, calculate pensions, manage insurance products, or track long-term securities.
These systems may have been accurate and reliable for decades, but they’ve become:
- Opaque
- Untestable
- Untouchabel
- Hard to staff
This puts business continuity at risk. If you lose your few people who understand the code, you may not be able to maintain or safely evolve the system.
01Opaque
Difficult to inspect or understand.
02Untestable
Lacking coverage and structure.
03Untouchable
No one wants to risk breaking them.
04Hard to staff
Few engineers know these languages today.
Modernizing your software creates huge business benefits
Further information
Here’s a useful tool that can be used outside its remit. It’s the UK government’s guide to evaluating the criticality of legacy-related risks across government departments.
ING Bank and Danske Bank core banking transformation case studies.
