The pricing of bonds or a Credit Portfolio usually has simple mathematics. However, when faced with a big portfolio, careful design is crucial for a fast execution time. I'll show how I designed a solution to price a database of about 2.4 million contracts with 78 million cashflows in up to 3.5 minutes using a 8 core machine. The solution uses plain simple Julia code, some parallel computation and buffering strategies, Julia's native serialization for fast-loading data from the disk, and a handful of packages. BusinessDays.jl and InterestRates.jl packages will be featured.