Sergio Roca Castellano is a pen name used by the founder and primary writer behind Kairo Diploma.
He completed the IB Diploma Programme in 2026, earning 42 out of 45 points, including 7s in Business Management HL, Mathematics: Applications and Interpretation HL, and Geography SL, along with an A in his Business Management Extended Essay.
During the Diploma Programme, he experienced first-hand how overwhelming the IB can feel without a clear sense of what examiners actually expect, how each assessment works, or where to find reliable, up-to-date guidance. He completed the full range of IB requirements himself — Internal Assessments, TOK, CAS, the Extended Essay, and final examinations — before going on to gain admission to the degree programme he had hoped to pursue.
He created Kairo Diploma shortly after finishing the IB, with a simple goal: to make the experience clearer for the students who come after him. Many of the topics covered on this site are built directly around the questions and uncertainties he ran into himself during the Diploma Programme.
Kairo Diploma doesn’t claim to replace official IB guidance. Sergio combines his own recent, first-hand experience as an IB student with research drawn from official and reliable sources, with the goal of helping current students make better-informed decisions — while always pointing back to official sources for anything time-sensitive or official.