Bioinformatics has a lot of data!
We aim to process data fast. Kotlin is compiled on the fly (or native compilation is also possible), which allows it to be much faster than Python (unless C code is directly accessed). Here are three examples: searching for 6bp palindromes; translating from DNA to protein; and complementing and reverse-complementing sequences.
When BioPython can rely on C code (e.g. complementation), BioKotlin is only 2.6-fold faster. In other cases, BioKotlin is nearly two orders of magnitude faster.
BioKotlin also stores DNA sequences with only 2 bits per bp, which can save 4- to 8-fold on RAM with only modest performance losses.