I don't think the fact that it did effectively:

    data_1 = `cat ./data1.json | grep "city" | awk ....`
    data_2 = `cat ./data2.json | grep "city" | awk ....`

was exactly helping it to perform well. I'm sure rewriting the rails app to load all the data at startup, not to read each file via several hundred subshells on each request, would have made it perform well enough.

However, pretty much no matter how well or poorly the rails site is built, a static site will be easier to run reliably.