Relocating a career across borders is six problems at once: visa, credential, language, tax-residency, professional registration, and network. The persona view structures each of the 100 subjects around these six dimensions for the major destinations.
Visa. Skilled-migration visas (Australia 482/186/189, Canada Express Entry, UK Skilled Worker, Germany Blue Card, Netherlands Highly Skilled Migrant, Singapore Employment Pass + ONE Pass, US H-1B + EB-2/EB-3) all have subject-specific point implications. Some subjects (medicine, engineering, IT, accounting) score higher; others have country-specific shortages with bonus points. Credential. Foreign-credential recognition is subject-specific and country-specific: medicine has the MCQ-bridges (PLAB, USMLE, AMC, MCCQE, MOH), engineering has the chartered-engineering bridges (Engineers Australia, Engineering Council UK, NCEES PE), accountancy has the credential-mapping treaties between major bodies (ICAI ↔ ICAEW ↔ CPA Australia ↔ CPA Canada partial pathways).
Language. Most jurisdictions require a language credential at A2–C1 level depending on the field; the language pathway adds 6–24 months to the relocation timeline. Tax residency. The country you live in for tax purposes is determined by day-counts, centre-of-vital-interests tests, and treaty tie-breakers — and it determines net income, social-security obligations and pension portability. Professional registration. Healthcare, law, engineering, architecture and education all require local registration with the relevant body, on top of the visa. Network. Every field has its diaspora — Indian Medical Association UK, IEEE chapters, ICAI overseas chapters, alumni networks of the major business schools. Joining the diaspora before the move accelerates the landing by 12–24 months.