He joined the Foundation in 1986 as Assistant Representative in Bangladesh and Nepal and later served as the Foundation's Country Representative in Sri Lanka and Maldives (1989-92), in Bangladesh (1992-97), and in the Philippines and Pacific Islands (1997-99).

Prior to joining the Foundation, Langton served with CARE in the US, worked with Ugandan refugees in southern Sudan and was a Peace Corps volunteer, trainer, and consultant in Nepal.