Explore soft deletes with isActive and discontinued, and implement delete by id in a NestJS sample, removing an array element with splice while testing via Postman.

Understand nest middleware runs before controllers, mirroring express. It can modify request or response and uses next() to continue, implemented as a function or injectable class for logging and auth.

Learn to create a custom exception hierarchy in NestJS, extend the base http exception, and throw a file not found exception to produce precise error responses in JSON.

Learn to build and apply custom exception filters in NestJS to take control of error handling, log details, and return structured JSON responses at the handler, controller, or global level.

Explore NestJS pipes, including built-in validation and transformation pipes, to convert inputs (like strings to numbers), apply default values, and handle pagination with page and limit parameters.

Discover MongoDB as a cross-platform, document-oriented NoSQL database, with collections of flexible documents and fast queries through sharding, while noting lack of transactions and joins.

Install MongoDB community server on your local machine, unzip the download, set the data directory, start mongod on port 27017, and connect with the mongo shell to view databases.

Create a new nest project with class-validator, class-transformer, and mongoose, install dependencies, run the dev server on port 3000, and scaffold context module, controller, and service.

Connect a NestJS app to a cloud MongoDB Atlas cluster, set up IP whitelisting and a user, and test get and post /contacts against the phonebook Contacts collection.

Deploy your app on Heroku, a platform as a service with managed containers and data services. Sign up for a free account to use the Heroku CLI.

Explore MongoDB's document model where collections hold dynamic BSON documents with varying field structures, and learn how single-document storage avoids joins, subqueries, and lacks transactions.

This lecture compares save() and insert() in MongoDB, showing insert creates a new document and may fail on duplicate _id, while save updates an existing document.

Use the $where operator to filter documents in the sales collection with a JavaScript condition evaluated on the current document, including equals and range checks.