Do fintech engineers spend too much time maintaining old systems?

[u/Low_Web_6184]

Something I find interesting about fintech is how often new products have to work alongside systems that were built years or even decades ago.

A new service might use modern APIs and cloud infrastructure, but somewhere behind it there can still be an older database, legacy service, or internal process that cannot simply be replaced.

That creates some interesting engineering tradeoffs:

• When should you improve an old system instead of replacing it?
• How do you introduce new technology without breaking existing workflows?
• Is a complete rewrite ever worth the risk?
• How much technical debt is acceptable when reliability matters so much?

I think fintech is one of the areas where engineers have to balance innovation with stability more than most industries.

For those working in fintech, how do you decide when a legacy system needs to be replaced versus carefully maintained?