Each month, about 50 million people visit Stack Overflow to learn, share, and build their careers. We estimate that 21 million of these people are professional developers and university-level students.
Our estimate of professional developers comes from the things people read and do when they visit Stack Overflow. We collect data on user activity to help surface jobs we think you might find interesting and questions we think you can answer. You can download and clear this data at any time.
Almost 60% of respondents identify as back-end developers, and about 20% consider themselves mobile developers. The median number of developer type identifications per respondent is 2, and the most common pairs are combinations of back-end, front-end, and full-stack developer. Pairs that are highly correlated are database administrator and system administrator, DevOps specialist and system administrator, and designer and front-end developer.
... read the whole story at insights.stackoverflow.com.