Aah he sounds like my son. He's a very lovely IT nerd currently at uni. Very very intelligent and interesting to talk to when you know him but his social skills in situations like this are lacking. He knows it, but it just doesn't come naturally to him at all because he doesn't know why other people who he probably won't meet again want to know such inane things about him. It's small talk to him. If you were to talk about something he finds interesting eg engineering, US politics, wine, travel, he'd probably have something to say. My son actually HASN'T got a holiday booked for this year, incidentally, if you had asked him that, but did travel last year, but you didn't ask him about last year and he is very literal in how he listens to questions.
TBH, your social skills seem quite basic too. It's a skill to draw out the inner thoughts of someone like that. You didn't expand on anything you had to say either and so the conversation had nowhere to go. If this guy was shy, it would be a help if you had taken the lead for a few minutes and talked more about things and let him listen, process and think. You could have just told him about YOUR holiday plans for this year, told him where you went last year or about where you'd like to go money no object, and this could have sparked some interest from this guy and given him an actual starting topic of discussion.
When you asked him about what type of software engineering he works in you could have said "oh come on, I'm a code nerd, too, it's all interesting to me. My current project is X/y/z, do you have any experience of that? I'm struggling with this aspect of it." Would have just given him more of an "in", and helped him to start to relax if he was a bit shy and anxious.
Incidentally, my son has a lovely girlfriend, who DOES see the inner him. They complement each other very well, and feel comfy just being themselves. But it takes a bit of effort to know someone who "runs a bit deeper". Depends if you can be bothered. Some people can't, and they're more comfy with others like them who can just chat shit lol.