Throughline

How we know

Every number on this site is a count of real job postings. This page explains exactly how the counting works, including where it is weak.

Where the postings come from

We sample live job postings through a licensed jobs API and read the text of each one. We do not scrape LinkedIn, ZipRecruiter, or any site whose terms prohibit it — not as a matter of caution but because the resulting data would be unusable to publish.

Occupation definitions, skills, and typical entry education come from O*NET. Certification and local training-provider data comes from CareerOneStop. Wage bands come from the Bureau of Labor Statistics Occupational Employment and Wage Statistics programme.

How credentials are counted

We maintain a catalogue of 61 credentials — certifications, licences, clearances, and degrees — each with the names employers actually write. A posting is matched against that list by exact name, not by a language model. That choice is deliberate: a model deciding whether a posting “mentions CCNA” is a black box you would have to take on faith. A name match is something you can check yourself.

A posting counts once per credential no matter how many times it repeats the name. The figure we publish is postings that mentioned it, out of the whole sample — including the postings that mentioned nothing at all, because those are evidence too. Dropping them would inflate every percentage here.

What “lower signal” means

A credential appearing in 10% or more of the sample is listed as something employers ask for. Below 5%, it is listed as lower signal for that specific role in that specific place. That is not a claim the credential is worthless — plenty of them are valuable for a different job, or a different city, or a promotion later.

We will not make the lower-signal call from a sample smaller than 40 postings, because at that size a single posting moves the percentage by more than the threshold does. When the sample is thin, the section is simply absent.

We sell no courses and take no fee from any certifying body, which is the only reason we can print that section at all.

Where this is weak

  • Samples are small. Each page states its exact sample size and date. A few dozen postings is a snapshot, not a census. We do not publish a page at all below 15 postings — at that size the percentage is mostly an artefact of the denominator, and printing the denominator underneath does not rescue it.
  • Postings are not jobs. They are what employers wrote down. Requirements listed as mandatory are frequently negotiable, and the reverse happens too.
  • Not every role and city is covered. Where we have no local sample we show national figures and label them as such rather than passing them off as local.
  • Costs drift. Every dollar figure carries the month we last checked it against the issuer’s own page. Confirm before you pay.

The disclaimer

Throughline is informational. It is not career counselling, and nothing here is a guarantee of employment, admission, or licensure. Verify requirements with the certifying body and your state before spending money.