The tutorial provides a step-by-step guide on building an efficient tool using Retool and Sequin to manage HubSpot leads, aimed at streamlining the sales team's workflow for enriching and qualifying new leads. Due to the lack of native HubSpot integration in Retool and the cumbersome nature of HubSpot's API, Sequin offers a solution by syncing HubSpot data to a Postgres database, allowing the use of SQL in Retool. The guide includes the setup of HubSpot and Sequin, the creation of a seamless interface for lead management in Retool, and the implementation of features such as searchable and filterable lead tables and form-based lead enrichment. Additionally, it demonstrates how to handle bulk actions efficiently, avoiding the limitations of HubSpot's API and enhancing the app's usability with customization options. The tutorial emphasizes ease of use by leveraging SQL and a bit of JavaScript, showcasing how internal tools can be developed without extensive reliance on HubSpot's API documentation, thus empowering teams to scale their inbound sales efforts effectively.