Personnel: Jeff Dean at Google DeepMind (Chief Scientist (Google Research / DeepMind))

NoteThe source directly confirms all key fields of the record: (1) person is Jeff Dean ✓, (2) org is Google DeepMind ✓ (formed April 2023 from merger), (3) role is Chief Scientist ✓ (explicitly stated: 'Dean became Google's chief scientist'), and (4) startDate is April 2023 ✓ (source states 'In April 2023'). The source also notes earlier that 'He was appointed Google's chief scientist in 2023 after the merger of DeepMind and Google Brain into Google DeepMind.' All claims are directly supported by the source text.