Externalities are believed to drive the productivity benefits of cities, and also of dense sub-parts within cities, e.g. the central business district (CBD). Recent research claims that density externalities accrue mostly to non-routine activities, and that their effects, e.g. human capital spillovers, attenuate sharply with distance. Consistent with these claims, I demonstrate strong clustering tendencies in non-routine professions as evidenced by job-switching patterns, specifically switchers’ distances moved between employers. Individual-level geo-coded data for switchers within Sweden’s metropolitan areas are used to illustrate that employees hired to non-routine occupations tend to switch to jobs close to the previous work establishment, while blue collar workers show dispersion. The differences are chiefly explained by (1) non-routine activities concentrate in the CBD (the strongest effect) and local employment centres, (2) non-routine activities cluster also outside of centres, and (3) industry-specific effects. The patterns are consistent with the importance of sharply attenuating non-market interactions (e.g. knowledge spillovers) in the production of non-routine products and services.