Is he into me? (Help)

I saw this guy at a conference & I thought omG hand-some! But I didn't say anything. Nearly a year later, in September 2017, we met at another one. I went downstairs to meet a friend of mine whom he works with, when they arrived for the meeting at my work place. I was talking to my friend & didn't say anything to the guy & when we got in the elevator, he looked at me & smiled & said hello & so I did the same. While we were waiting at the lounge upstairs for another meeting to be over, the other guy (My friend) sat across from me & we were talking & he came over & sat next to me & joined the convo. A little while later, they headed back down to the main meeting & I went back to my office promising to meet my friend later to go to the movies.

So in the evening after work, I dropped by the hotel lobby where my friend was staying, sent him a text that I was waiting for him to meet me so we could head to the movies & waited. This other guy saw me from across the room, waved & I waved back. He came over & sat next to me talking to me, his body facing me at a point he said "you're a smart girl..." (compliments) & in the end he asked for *all* my numbers (I interpreted it to mean he really wanted to stay in touch). I gave them all to him then said okay beep me & I'll get yours too. He didn't do so right away, he sent it to me much later that evening about 3 hours later (possibly the art of seduction.. I don't know. lol). He was meant to travel back the next day so I waited until I was sure he had landed & had time & I messaged him checking he had a pleasant trip & he responded, in the end he said "don't be a stranger" I'm assuming that's American for "keep in touch" yes? So we kept messaging sometimes & once in a while he would call me (he called me a total of three times so far). Sometimes though he just goes mute & I don't hear from him. Then after like a few weeks or so he beeps me. He wanted to meet up when I told him I was travelling about 3 different times because he was meant to go to all those places around the time too although he was busy the 1st time the whole couple of days when I went to London so he suggested we'd meet up when I returned cos he'd be there around the same time. Anyway, during the 2nd & 3rd times, his plans changed from work & he had to travel elsewhere so we didn't meet up. We live in different countries. He's still doing the 'awol' right now. I've resolved to just let things be what they'll be.

But I really want to know, does it appear he is interested? Or was he just being friendly?