After around a month of 2-hour/day work, two days ago I launched TravelFreedom.io! I created it using only Jekyll, and data files as "database". While I hope it will be a useful service, it was also a good project to discover Jekyll and see what it is capable of.
Further lessons learned:
Static site generators - Unless it's something that takes user data and processes HUGE amounts of data, you must really consider static site generators to traditional CMS solutions.
Lean principle See it yourself - I initially wanted to get travel data automatically from IATA, but I decided against it since I saw some inconsistencies. I've decided to manually enter visa policy data using helper scripts, and it was a really good decision I made. Going over different visa policies I saw that things aren't as simple as visa-free or visa-required. Some countries require electronic authorization, which is not guaranteed. Some countries allow more passports during summer and some countries even totally ban entry. I had to make a case for each of these different possibilities and come up with a model that would consider all these nuances. Toyota managers are totally right - knowing tiny details of your business is tremendously helpful.
Incremental launch - Though I want to push the idea as soon as possible, I realized that I may need to update many things on the go. One of first 5 people who looked at the website already noticed an error I had to fix, so I understood the website needs to become a bit more mature.