Software development for small- to medium-sized businesses, non-profit organizations, and research institutions, drawing on experience earned by contributing to open source projects.

15+ years of contributions to renowned projects such as Subversion and OpenBSD.

Experienced in networking software, device drivers, developer tooling, databases, application software, defensive security, and code review. See the projects page for details.


First-hand expertise in Subversion and Git, from the user interface down to implementation details. Knowledge transfer lets your team work effectively using best practices.

Smooth repository server migrations from any to any version control system. Legacy Subversion server upgrades.

OpenBSD redundant firewall setup and maintenance, VPN, wireless and wired routers.

Coaching OpenBSD system administrators.


Chirpy Software was founded in 2024 by Stefan Sperling. Currently operating as a single-person business. The long-term vision includes building a team. Get in touch if you are interested.

New project proposals are always welcome. See the projects page about past and on-going projects.