new testimonial

_testimonials/jozef-rudy.md

@@ -0,0 +1,25 @@
+---
+id: jozef-rudy
+bullets:
+- '**Jozef Rudy, PhD**'
+- Founder
+- '[CryptoQuant](https://www.cryptoquant.dev)'
+keywords:
+- startup
+- fintech
+- trading
+- cryptocurrencies
+quote: F# is more flexible than C#, yet gives stronger type safety. It allows for fearless refactoring, which is also easier because of naturally less coupled code while at the same time codebase being 40%-size of equivalent c# one.
+
+---
+I first ventured into F# while working at a US-based startup where one of our servers handling PnL calculations was performing sub-optimally.
+I decided to re-write that in F# as a test. I was surprised that without requiring any special libraries (unlike the Python version that relied on pandas and numpy) the F# code was similarly concise yet significantly more performant.
+
+When I started [CryptoQuant](https://cryptoquant.dev), which allows backtesting and live testing of trading strategies on cryptocurrencies, I started writing just the trading rule parser in F#.
+
+The illustration of the first version of the parser can be found on my public git [repo](https://github.com/jozefRudy/trading-rule-parser).
+It parses subset of Typescript into F# interpretable AST, which can later be evaluated against data to calculate entry/exit signals.
+
+Because parsing with Fparsec went so well I later gradually migrated entire project into F# (from C#).
+The beauty of this approach is that I don't need any specialized F# libraries - I can stay very close to the original (C#) dotnet server, avoiding dependency on specialized F# third-party packages.
+I can still use great dotnet server features like background jobs or dependency injection.