Kristof Martas focused on hardening the browser and UMD build process for the apify-client-js repository, addressing stability issues that affected integration with modern bundlers and ES module consumers. By switching the build to production mode and setting globalThis as the global object, Kristof resolved compatibility problems that previously caused failures in strict ES module contexts. The work involved removing development-mode hot module replacement code from the distribution bundle, which improved reliability for downstream users. Utilizing TypeScript and build configuration expertise, Kristof’s targeted bug fix enhanced the robustness of front end integrations, ensuring smoother adoption in diverse JavaScript environments.