Pioneer Square Labs | 14,408 followers on LinkedIn. PSL is a startup studio and early-stage venture capital fund in Seattle, WA. | Pioneer Square Labs is a Seattle-based studio that creates and launches technology startups. We are funded by 14 VCs and 50 angel investors from Seattle, Silicon Valley, Colorado and other parts of the country. Companies created: - LumaTax (http://lumatax.com) allows small business owners to file their sales tax with ease