As a programmer, you may be asked to take over or add on to websites that have been programmed by another company or a freelance programmer. When working with someone else’s code it may take you a bit to get your head around how they have done it and, depending on how they work, it may need a bit of tidying up.
When you are quoting for work to be done on a website that you have not programmed it is important to include additional time for this or to inform the customer that there may be additional costs should it not be as straightforward as it should be.
You need to take some time to familiarise yourself with the layout and set up of the website and try and figure out how the main elements work and have been put together. Understanding how a website has been programmed will often mean that all jobs on the site become a little bit easier.
When working with someone else code, never assume anything. If you have taken the project over then the client will expect you to take responsibility for it from then on. Always thoroughly test your work before it goes live and checks that any changes you do do not affect other parts of the site.