Who is Mustafa Kose?
Mustafa Kose is the founder and developer of VirtuoLab, a software agency in Papendrecht, the Netherlands. VirtuoLab is a sole proprietorship, registered with the Dutch Chamber of Commerce under number 94892083. Mustafa Kose runs the business alone and does the work personally, from the first intake call to the launch and the support afterwards. Clients therefore speak with the developer who writes the code, not with an account manager. Mustafa Kose builds software with React, Next.js and TypeScript and works in Dutch, English and German. On location, meetings take place in the Drechtsteden and in Rotterdam. Online, Mustafa Kose works with businesses across the Netherlands, Belgium and Germany. Additionally, Mustafa Kose writes the articles on the VirtuoLab blog. Topics include, for example, the cost of a web app, the choice between React, Angular and Vue, and visibility in Google and AI assistants such as ChatGPT. The articles by Mustafa Kose explain technical choices in plain language, with indicative prices for 2026.
What does Mustafa Kose build?
Mustafa Kose builds custom software for small and medium-sized businesses: web apps, mobile apps, SaaS platforms, API integrations, WordPress plugins, Power BI dashboards and websites. A web app is software in the browser, such as a client portal, a planning tool or an internal dashboard. First, for the web, Mustafa Kose works with React, Next.js, TypeScript and Node.js, with PostgreSQL or MongoDB as the database. Second, mobile apps are built with React Native or Flutter (Google) for iOS and Android at once, or with Swift (Apple) for native iOS. Third, integrations connect systems through REST or GraphQL APIs. Additionally, dashboards are built in Microsoft Power BI or as a custom React dashboard, and custom plugins are written for WordPress, WooCommerce and Shopify. Python, Docker and AWS complete the stack. For example, the VirtuoBI demo on virtuolab.dev is a sales report in Power BI style, built with React on fictional data for 2023 to 2025. All demos are concepts built by VirtuoLab on simulated data, not client work; VirtuoLab also builds and runs two products of its own, FiscalDesk and Bouwklok.
How does Mustafa Kose work with clients?
Mustafa Kose works with clients in four steps, with a fixed price agreed before development starts. Step 1 is a free intake call about the goal, the users and the budget, followed by a written scope. Step 2 is design and validation: screens and flows are checked with the client before anything is built. Step 3 is building and testing in short sprints, with a working demo after each sprint. Finally, step 4 is the launch, the handover of the source code and the data, and support afterwards. The client speaks with Mustafa Kose directly at every step, by phone, email, video call or on location in the Drechtsteden and Rotterdam. In practice, a question about a Next.js web app or a Microsoft Power BI dashboard is answered by the person who wrote the code. Because Mustafa Kose works alone, capacity is limited, so the start date and the planning are agreed upfront. In 2026, VirtuoLab is reachable from Monday to Friday, 09:00 to 18:00.