This looks like a bug:
The company "Which?" is appearing in the "company spotlight" sidebar. If you click the logo or the "View which? job listings »" link you arrive at the job search page which has zero results.
This answer to the "Q: Is company spotlight payed per job listing?" question indicates that a company needs to have at least one live job listing to appear in the "company spotlight" sidebar:
A: Is company spotlight payed per job listing?
This Bug Report is not about the encoding of the link
The link encoding discussed in the comments was a red herring.
The links I copied had the encoded question mark "?". The reason they weren't encoded after I added them to my question is that the system unencodes the entity if you use the "Hyperlink button" or Ctrl+L to add a link to the selected text. See this question for further info:
Hyperlink button breaks some URLs when automatically undoing URL encoding
The actual bug that was being reported:
The bug is that companies are appearing in the "company spotlight" sidebar even when they don't have any job listings. The links under the company info in the sidebar say:
View "Company Name" job listings »
Which means that there should be job listings. See original question at top for link to answer that says a company must have at least on job listing to appear in the sidebar.
This bug Is Reproducible
By hitting reload numerous times on the careers home page, I was just able to find instances of three companies being shown in the sidebar even though they don't have any job listings. You need to be logged in to see this. When I tried without logging in, the company in the sidebar never changed even though I reloaded the page numerous times.
I've taken screen shots of the home page with each company in the sidebar and then of the jobs listing page that is linked to from the sidebar: