Writing a custom solver seems kind of absurd to me. There are 10s(/100s?) of open source ones out there. HiGHS in particular seems to be challenging the paid so

Writing a custom solver seems kind of absurd to me. There are 10s(/100s?) of open source ones out there. HiGHS in particular seems to be challenging the paid solvers with its LP improvements of late. But now I want to write my own.