Optimize Dedicated Server for Speed

Job ID: 35503398

Budget: $30 – $250 USD

There is a web application seating on a Dedicated Server with Bluehost. It is already very slow (often times inaccessible) with few thousand visitors. I seek an expert who knows what to do to grant optimal speed for accessing the web application, and advice on best practices to stay optimized.
Related categories: PHP System Admin Linux Web Hosting DevOps