Yip dealing with a code base right now that's like this. Devs do this for job security. Make the thing incomprehensible to others guarantees you can't be fired right? It also guarantees a promotion right up to team lead or dev manager.
Another note it's not what's the best SOLID design it's what that original dev thinks is the best SOLID design. SOLID in itself is loose enough that you can have designs that vary massively but are still technically SOLID.
Another note it's not what's the best SOLID design it's what that original dev thinks is the best SOLID design. SOLID in itself is loose enough that you can have designs that vary massively but are still technically SOLID.