The airport is mostly new after months of renovation and expansion. As usual now both domestic and intl passengers undergo passport control and customs either departing or arriving. Make sure when departing to get your tourist permit and your passport stamped. Immigration personnel were friendly but the lady at Customs wasn't. I usually get immigration cleared at the land border point when coming from San Diego but the office at the border closes at night TIJ Immigration is 24/7 so no worries for late night/early morning flight. Check-in is a bit messy - though not slow - with Volaris the largest tenant but otherwise smooth with other carriers. If you fly Aeromexico well let's say I've enjoyed better lounges than theirs at terminal A. Better spend time at the terminal's Starbucks. Food is the airport biggest failure (small gates too perhaps) I believe with nothing other than the aforementioned cafe and some overpriced bad tasting and cramped "restaurants". Terminal B isn't any better at food; its upside is a great local wine shop. Free wifi available everywhere.