Start from the apply link, not the posting
The apply button usually leaves the job board and lands on the software the employer actually uses. That destination host tells you which system to search, and it is far more reliable than searching the company name and hoping.
Greenhouse, Lever, Ashby, Workable, Recruitee, SmartRecruiters
All six publish a complete public list of open roles. Strip the URL back to the company part and you get the whole board: every open posting, nothing hidden. If the role is not on that list, the version you were reading has outlived its source. This is the same list our own check reads.
Workday, iCIMS, Teamtailor and the rest
These publish no straightforward list, so search the careers site by title and location instead. Absence is weaker evidence here: a search that finds nothing may be the search failing rather than the posting being gone.
What an absence does and does not prove
A posting missing from a complete board is strong evidence it has closed. A posting missing from a board you could not fully read proves nothing, which is why our own check refuses to score absence when a vendor paginates and we did not finish reading. Treat a short or truncated list the same way.