What skills are used in programming? And which cities excel at which kind of software development work? To analyze this, we construct a taxonomy of 237 distinct programming skills from the digital traces that millions of software developers leave on Stack Overflow, the software development community’s largest online Question-and-Answer platform. We map these developers’ human capital in a software skill space, connecting skills that are closely related. Only a small share of software developers contribute to Stack Overflow and the data only speak about those who do. However, the sheer volume of contributors and their distribution around the globe allows analyzing work in software development in great detail for almost a thousand cities worldwide, covering 15 years’ worth of transformation of the sector’s labor market.

Publication

Xiangnan Feng, Johannes Wachs, Simone Daniotti, Frank Neffke. (2026). Using digital traces to analyze software work: skills, careers and programming languages. arXiv. arXiv:2504.03581

Johannes Wachs, Xiangnan Feng, Simone Daniotti, Frank Neffke. (2026). The Changing Global Division of Labor in Software: Emergence and Diffusion of New Programming Skills across IT Hubs. arXiv.arXiv:2606.09463v1

This research was supported by the Austrian Research Promotion Agency (FFG), project #873927 (ESSENCSE) and funded in part by the Austrian Science Fund (FWF) and netidee Science 10.55776/PAT2054025.