I'm Mara Whitlock, the writer behind Cairnroam's U.S. edition. I grew up in Austin, Texas and now split my time between San Francisco and wherever the next trip takes me.

My eSIM obsession started with a painful $1,400 roaming bill on a single summer trip. After that I set out to learn exactly how staying connected abroad really works — carrier by carrier, country by country. Since then I've tested eSIMs, local prepaid SIMs, and carrier day-passes across more than 40 countries, always from the ground, phone in hand, at the arrivals hall.

On Cairnroam I write numbers-first, plain-spoken guides for American travelers: what a plan actually costs, where it breaks, and what I'd personally pack for a trip. No sponsored fluff — just what worked and what didn't.