There is no DynamoDB API to query multiple items by primary key in a single operation. However BatchGetItemCommand can be used to batch multiple read requests and get up to 100 items.

Write transactions are supported in DynamoDB's Node SDK via the TransactWriteItemsCommand method. Transactions can include up to 100 insert, update or delete operations. Either all of the operations will be successful or nothing will be successful.

DynamoDB has a maximum limit of 1 MB in its Query or Scan API responses. To get the full data we need to make use of the LastEvaluatedKey response attribute.

Tables can be created in DynamoDB using the CreateTableCommand() method of the AWS DynamoDB Javascript SDK.

We can check whether specific DynamoDB tables exist using the AWS Javascript SDK. The ListTablesCommand method can be used to list DynamoDB tables in a region.

This tutorial discusses installation of AWS Node.js SDK and getting started with it.

The toLocaleString() method of the Date() object can be used to get date and time for a given IANA timezone name in Node.

Node.js does not support the standard Javascript methods of atob() and btoa() for base64 conversions. Encoding and decoding base64 data in Node can be done through the inbuilt Buffer module.

In Node.js date and time are handled with the Javascript Date object. It is loaded by default and requires no import of modules.

The built-in http / https modules can be used to create a HTTP / HTTPS server in Node.

A synchronous HTTP request will wait for the request to be made and full response to come. Synchronous HTTP requests are possible in Node.js with the use of Javascript Promises, async and await.

HTTP GET requests can be made through Node using the http module.

This tutorial discusses how to send a HTTP POST request from Node using the http module.

Cron jobs are important when some script is required to be executed at a fixed time over and over again. In Node.js cron jobs can be setup using an external module known as node-cron.

JSON.parse accepts an optional second parameter - the reviver function. The purpose of this function is to modify the result before returning, and can be thought of as filter function.

The standard built-in Javascript object JSON can be used to parse json strings.

The "xml2js" module can be used to read XML files in Node. In case if the file is huge, the "node-xml-stream" module can be used to read XML as a stream.

The Sharp module can be used to crop an image in Node.

The Sharp Node.js module can be used to resize large images of any common file-type to web-friendly images of any dimension. It claims to be multiple times faster than ImageMagick and GraphicsMagick.

In some cases you may need to read a file, line by line, asynchronously. This can be done by the Readline module that reads data from a readable stream and emits an event after reading each line.