Belgium is small enough to drive across in a few hours, but its interview culture splits sharply along regional lines, and treating the whole country as one culture is a common, avoidable mistake.
One country, two very different interview cultures
Flanders, the Dutch-speaking north, tends to run flat and relatively informal organizations, decisions made as a team, first names common, direct and efficient communication prized, especially in tech and startups. Wallonia, the French-speaking south, tends to be more formal and hierarchical, with more traditional leadership styles, job titles carrying real status, and formal address expected, at least initially. Brussels sits in between, commonly bilingual and often comfortable running in English, particularly at international employers. Before an interview, it is worth finding out which region and culture you are actually walking into, since the right tone for Antwerp is not necessarily the right tone for Liège.
Get the regional language right
Language is not a minor detail in Belgium, it is a genuine cultural fault line. Use Dutch, and the formal "u", in Flanders, and French, with the formal "vous", in Wallonia, speaking the other region's language uninvited can cause real offence rather than reading as effort. CVs should generally be written in the correct regional language too: Dutch for Flanders, French for Wallonia, and French or English for Brussels. If you are unsure which applies to a specific employer, it is worth asking directly rather than guessing, since getting this wrong before you even reach the interview can undercut an otherwise strong application.
The Single Permit and EU Blue Card
For non-EU candidates staying longer than 90 days, the Single Permit is the standard route, combining work and residence authorization into one application and one card. The employer files with the competent Belgian region, and federal and regional authorities jointly decide within a set window, generally around four months. Salary thresholds for skilled roles vary by region, for example, highly skilled workers in Brussels need to meet a set monthly minimum to qualify. The EU Blue Card runs alongside this system for highly skilled professionals with a recognised degree or several years of relevant ICT or comparable experience, with its own, generally higher, regional salary thresholds and the benefit of easier onward mobility within the EU. If sponsorship applies to your situation, it is worth knowing which route and which region your offer sits in before the interview.