I have been through 5 onsite loops in the last 90 days. Different companies, different stages, different formats. Three offers, two rejections. I took notes inside each loop — what came when, who I met, what they asked, how long it ran. This post is the comparison. If you are about to walk into your first senior onsite of 2026, this is what the variance actually looks like. The five loops I'll describe the loops by stage, not by name (companies asked). Loop A — FAANG-scale public company, senior backend role Loop B — Mid-cap public, infrastructure team Loop C — Late-stage private (~2000 engineers), platform role Loop D — Series C startup (~150 engineers), staff-track backend Loop E — Series A startup (~30 engineers), tech-lead role Loop A — FAANG, 6 hours A single Friday, 9am-3pm. Five interviews back-to-back, 50 minutes each, with 10-min breaks. Lunch was solo at the desk — not optional, just nobody scheduled time for it.…