In April 2025, Eszabo worked on the HubSpot/slack-client repository, focusing on backend development using Java. They addressed a critical issue in block processing by adding the missing 'Call' subtype to Block.java, which enabled the system to correctly recognize and handle Call blocks within Slack message payloads. This fix improved the reliability of block parsing and reduced downstream processing errors, directly stabilizing analytics pipelines that depend on accurate block-type detection. Eszabo demonstrated strong skills in Java, parsing logic for complex data structures, and disciplined code maintenance within a Git-based workflow, contributing to the robustness of real-time messaging integrations.