I used to work for a company which the founder (and original engineer) was both very curious about how compilers worked and paranoid about having the company's code base stolen. That came to fruition with the following idea: "if I develop my own language and compiler, even if someone steals part of the code they still won't be able to run without the language specification and compiler!".
He designed his own programming language, compiler and, why not, the database and tools as well. It was a mess. It got all the limitations of a poorly projected side project and no benefit in the long run besides from huge technical debt.
15 years later, with dozens of clients' sites with the software installed and running locally, the company was locked in a horrible software stack that was next to impossible to move away from by gradually replacing modules, because the programming language had zero interoperability, the original creator was retired and no one besides himself had worked on it for years; while continue giving support to existing customers, because there were fires everyday, and with the same engineering team headcount.
That is one of the top 5 "oh my" in my career. I'm glad I left that behind.
Clojure's Rich Hickey? No. I'm not too familiar with him or Clojure, but it seems he put a lot more thought on it than the co-founder in my story could ever dream of.
He designed his own programming language, compiler and, why not, the database and tools as well. It was a mess. It got all the limitations of a poorly projected side project and no benefit in the long run besides from huge technical debt.
15 years later, with dozens of clients' sites with the software installed and running locally, the company was locked in a horrible software stack that was next to impossible to move away from by gradually replacing modules, because the programming language had zero interoperability, the original creator was retired and no one besides himself had worked on it for years; while continue giving support to existing customers, because there were fires everyday, and with the same engineering team headcount.
That is one of the top 5 "oh my" in my career. I'm glad I left that behind.