In this work interviews with developers were performed to learn about one aspect of modern web technology: Single Page Application and what the benefits and drawbacks are of that.Single Page Application or SPA is such website which is built with only single HTML file. Single Page Application is very important technology in nowadays web development. Compared to traditional Multi-Paged Applications, Single Page Applications have a lot of benefits. In traditional MPA, a new page will be rendered again when user performs specific actions like clicking a link. On the other hand, in SPA reloading entire page is not necessary and it can provide much better user experience to users. However, that does not mean SPA is a perfect solution. It has drawbacks too such as Search Engine Optimization, SEO. SEO is a problem for SPA because in SPAs, contents are rendered by client-side JavaScript and search engine crawlers cannot understand contents rendered by client-side JavaScript.  Nowadays a lot of JavaScript frameworks and libraries exist which are being used for developing Single Page Applications. For example, ReactJS, Vue.js, Angular and Svelte. Since SEO is not perfectly suitable in SPA, such frameworks usually also have solutions to SEO issues like Server-Side Rendering or pre-rendering. an qualitative approach was taken where interviews were conducted with developers who have experience in SPA development. It was hard to find respondent but eventually there were 4 semi-structured interviews, all conducted through videoconferencing. According to participants’ answers, there are a lot of ways to improve SEO in SPA made with JavaScript frameworks. For example, Server-Side Rendering and Pre-rendering. Each framework implements these technologies in its own ways. Web accessibility is also very important to get higher position in search result.