Can you explain some techniques you have used to increase performance when building a new web site or maintaining one?

 Questions: 

When building a new web site or maintaining one, can you explain some techniques you have used to increase performance?

Here are some techniques that I have used to increase the performance of web sites:

Minification: Remove any unnecessary characters from HTML, CSS, and JavaScript files, such as white space and comments, to reduce their size. Google provides the PageSpeed Insights Chrome extension, which recommends performance improvements to any website. PageSpeed Insights provides a “Minify HTML” rule which generates a minified version of the open website. CSS Minifier is a quick way to minify CSS. Also Refresh-SF uses some tools to minify CSS, HTML and JavaScript.

Compression: Compress assets, such as images, using tools like Gzip to reduce their size and speed up download times. Some documents, size reduction of up to 70% lowers the bandwidth capacity needs. 

Image Optimization: Reduce image file sizes by compressing them, using appropriate image formats, and resizing images to the exact dimensions required. Image optimization is the process of reducing the file size of an image while maintaining its quality. The goal of image optimization is to reduce the page load time and improve website performance, which can have a positive impact on user experience, search engine rankings, and conversion rates. Image optimization can be done through various techniques such as resizing, compressing, and converting to more efficient image formats (e.g. WebP).

Lazy Loading: Load images and videos only when they are needed, instead of loading all assets when the page first loads.

Cache Control: Specify a cache policy for assets using HTTP headers, such as "Expires" or "Cache-Control". This allows assets to be cached by the browser, reducing the number of requests to the server and speeding up page load times.

CDN (Content Delivery Network): Use a CDN to distribute assets and resources to users from multiple servers in different locations, reducing the distance between the user and the asset, and improving load times. You can use Amazon CloudFront as example of such network

Reduce the number of requests: Minimize the number of requests by combining CSS and JavaScript files, or using CSS sprites to combine multiple images into a single file. 

Use a fast web server: Choose a fast and efficient web server, such as NGINX or Apache or may be special server types, to serve your pages.

Enable browser caching: Specify a cache policy for your pages using HTTP headers, such as "Expires" or "Cache-Control". This allows pages to be cached by the browser, reducing the number of requests to the server and speeding up page load times.

Optimize database queries: Use efficient database queries, and avoid complex nested queries, to reduce the load on the database and speed up page load times. Use database clusters, split data if possible for read only access and share them from several database nodes.