Object-Oriented Programming — what it promised, what it delivered, what it broke, and what we quietly kept anyway
A Note Before We Begin
This is not a literature review. It is not a polished academic paper. It is a practitioner’s reckoning — written by someone who spent the better part of the late 1990s and early 2000s deep inside projects that were, in retrospect, genuinely obsessed with Object-Oriented Programming. Not always in the right way.
This paper presents Practical Work — derived from applying functional programming to production trading and risk systems. The patterns are grounded in real deployments across commodity desks, credit portfolios, and multi-asset pricing engines.
Topics Covered
Immutable data structures for market-data pipelines
Composable pricing functions and curve construction
Type-driven modelling of financial instruments
Scheme 48
Testing strategies for stochastic models
Background
The ideas emerged from more than a decade of building pricing and risk infrastructure at HVB/UniCredit , where the gap between theoretical elegance and production constraints is very real.