The blog post details the process of building an application to sync Google and Outlook calendars using the Nylas API V3, with a focus on integrating calendars from different providers. It outlines the steps to set up both Google and Azure applications and test their integrations using the Nylas Dashboard. The front-end is built using Next.js, hosted on Vercel, and connects users via Nylas' Hosted Authentication, which requires setting up a serverless function to handle authentication callbacks and retrieve user access tokens. The backend, also managed on Vercel, retrieves calendar events using the Nylas API, storing them in a Supabase database, which serves as a persistence layer for calendar data. The front-end then retrieves and displays these events using the React-Big-Calendar library, allowing users to view calendar events from multiple accounts. The blog post provides code samples and encourages further exploration of Nylas' capabilities through their documentation and free sign-up options.