This page is logistics, not an invitation and not a safety rating. Whether you travel is a decision for you and your government's current advice. Ukrainian airspace has been closed for long stretches; long-distance movement that still happens is often rail. Ukrzaliznytsia tickets live in an app as a QR code. You still show a passport that matches the name on the ticket.
Pay in hryvnia. Cards work in many city shops; keep some cash for small stalls and when a terminal is down. Ukrainian is the language of signs and announcements. Translation on a working phone is a practical tool, not a gimmick. Air-alert apps are how a lot of people get a siren on a lock screen — install what locals tell you to install, and follow official instructions if one sounds.
Curfews, documents and which stations are running change. Check a primary source the morning you move. Eat varenyky and borshch because that is the food, not because a brochure sold you a 'resilient city break.' An eSIM is useful for tickets, maps and messages. It is not a plan for a journey you have not cleared with official advice.