Shipvane · 4 AE roles
Marco E. · joined Cargolio
Fleetora · first roles in DECompanies using z/OS_
As of 4 November 2026, 257 companies name z/OS in their own job postings; it leaves no trace on websites or in DNS.
As of 4 November 2026 · refreshed daily · counts move as websites, DNS and career sites are re-read.
- Largest market
- –
- Companies with 51+ staff
- –
- Top industry
- –
- Team that names it most
- IT operations & business systems · 567 postings
- Hiring on it, last 30 days
- 289 companies
- Most often alongside
- IBM Db2 · 336 companies
Where z/OS shows up
Each population is counted on its own. We never add them up without saying so, because they answer different questions.
Companies whose own pages load z/OS's scripts or embeds, or whose domain's mail and hosting records (SPF, DKIM, MX, CNAME) point at z/OS. From our crawl of 41.5M company websites and the DNS sweep behind it. Reach: the tool is in the building.
Companies whose own postings say the team works in z/OS. Read hourly from ~70 applicant tracking systems, with the function, a quote and a date. Intent: the team that runs it is hiring.
Companies in the footprint whose postings also name z/OS. The rest of the posting population (257) runs z/OS without a public trace on the site or in DNS, which is where job data earns its place.
Companies on z/OS
Companies with 201+ employees and high-confidence evidence in their own postings; job boards and portals left out.
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Who runs z/OS inside the company
The 257 companies whose postings name z/OS: by country, size and the function of the role. The second number in the function table is companies.
| postings · companies | |
|---|---|
| IT operations & business systems | 567 · 236 |
| Software engineering | 457 · 198 |
| Product, program & project management | 47 · 38 |
| Engineering (non-software) | 41 · 27 |
| Data & AI | 19 · 15 |
| Finance & accounting | 13 · 8 |
| manufacturing and production | 12 · 6 |
| Unclassified | 5 · 4 |
| Sales | 4 · 4 |
| Customer service & success | 3 · 3 |
| companies | share | |
|---|---|---|
| United States | 128 | 50% |
| France | 24 | 9% |
| Germany | 14 | 5% |
| United Kingdom | 8 | 3% |
| Australia | 6 | 2% |
| Portugal | 5 | 2% |
| Canada | 4 | 2% |
| Denmark | 4 | 2% |
| Spain | 4 | 2% |
| Poland | 4 | 2% |
| Sweden | 4 | 2% |
| Belgium | 3 | 1% |
| companies | share | |
|---|---|---|
| Self-employed | 4 | 2% |
| 2-10 employees | 15 | 6% |
| 11-50 employees | 32 | 12% |
| 51-200 employees | 36 | 14% |
| 201-500 employees | 24 | 9% |
| 501-1000 employees | 23 | 9% |
| 1001-5000 employees | 34 | 13% |
| 5001-10000 employees | 14 | 5% |
| 10,001+ employees | 75 | 29% |
| postings | |
|---|---|
| Postings, last 30 days | 779 |
| Postings, last 90 days | 1,045 |
| All open postings | 1,637 |
289 companies opened a role that names z/OS in the last 30 days. A hiring team that names its tools is the moment to write to the person who owns the stack.
What z/OS teams also ask for
Tools named in the same postings as z/OS. Office software is left out.
z/OS against the rest of its category
Ranked by companies naming each tool in postings. Whole category →
Quote the sentence with the date and the link. The numbers change daily; the link always shows the current ones.
257 companies name z/OS in their own job postings; it leaves no trace on websites or in DNS, so the posting layer is the whole picture. (Breaknorm, 4 November 2026, https://breaknorm.co/tools/z-os)
Read from the source, not self-reported
Every number on this page can be traced to a page we crawled or a posting we read. Full methodology →
- Website codeScripts, tags and embeds found on the company's own pages in our crawl of 41.5M sites. A tool counts once per company.
- DNS recordsSPF includes, DKIM selectors, MX and CNAME records of the company's domain that point at z/OS or another vendor. Swept in cycles; dedicated mail-provider and hosting facets open once coverage passes 80% per country.
- Job postingsRead hourly from the applicant tracking systems behind company career sites. A tool counts when the employer's own text names it as the team's system; candidate wish-lists and apply boilerplate are excluded. Confidence low, medium or high per company.
- Sending infrastructureCold-e-mail sending domains are look-alike domains on a provider's infrastructure (DNS records, certificate logs) that redirect to the company. Absence is not evidence: only companies with a found sending domain are counted.
- CompaniesCountry, size and industry come from the company profile we build from its website; headcount from LinkedIn where known, otherwise estimated. Job boards, portals and aggregators are kept out of lists.
z/OS data: questions
How many companies use z/OS?
257 as of 4 November 2026: 0 carry z/OS on their website or in their DNS records and 257 name it in their own job postings; 0 show up in both. We keep the two counts apart because they measure different things.
What does "website or DNS" mean?
Our crawler finds z/OS's scripts, embeds and tags on the company's own pages, and our DNS sweep reads the domain's mail and hosting records (SPF includes, DKIM selectors, MX, CNAMEs) that point at z/OS. Either one puts the company in the footprint. The sweep is still running, so this number grows week by week.
Why is the job-posting number so much smaller?
A posting only names a tool when the team that will use it is hiring and chooses to say so. That makes it a smaller but stronger signal: it tells you which team runs z/OS, with a quote and a date. The footprint tells you reach.
How fresh is this?
Career sites are read hourly, websites are re-crawled on a rolling schedule and DNS is re-swept in cycles. The date at the top is when these counts were computed.
Can I get the list?
Yes. The first 20 are on this page; the full 257 with verified e-mails and a weekly feed of new z/OS users is in the product. Counting is free.
Get this list your way
The same data as a search, over MCP and the API, as bulk files, or pushed to you as it changes.
Every company on z/OS,
with the person who owns it
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