Tools · requirements mbse

Companies using IBM Rational_

As of 4 November 2026, 63 companies name IBM Rational 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
Software engineering · 131 postings
Hiring on it, last 30 days
43 companies
Most often alongside
Java · 35 companies
63companies show IBM Rational, all sources
0on their website or in DNS records
63name it in their own job postings
138postings naming IBM Rational, last 90 days
02 — Two ways we see a tool

Where IBM Rational shows up

Each population is counted on its own. We never add them up without saying so, because they answer different questions.

Website and DNS footprint0

Companies whose own pages load IBM Rational's scripts or embeds, or whose domain's mail and hosting records (SPF, DKIM, MX, CNAME) point at IBM Rational. From our crawl of 41.5M company websites and the DNS sweep behind it. Reach: the tool is in the building.

Job postings63

Companies whose own postings say the team works in IBM Rational. Read hourly from ~70 applicant tracking systems, with the function, a quote and a date. Intent: the team that runs it is hiring.

Both0

Companies in the footprint whose postings also name IBM Rational. The rest of the posting population (63) runs IBM Rational without a public trace on the site or in DNS, which is where job data earns its place.

03 — Who uses it

Companies on IBM Rational

Companies with 51+ employees and at least medium-confidence evidence in their own postings; job boards and portals left out.

Global Payments IntegratedOnline payment gateways · United States10,001+ employeesQuestronixIT services & consulting · Makati City, PH51-200 employeesNorthrop GrummanDefence systems manufacturers · Falls Church, United States10,001+ employeesFlightSafety InternationalFlight training schools · United States1001-5000 employeesSTRDefence systems manufacturers · Arlington, United States501-1000 employeesRightStarIT services & consulting · United States51-200 employeesTermaDefence systems manufacturers · Lystrup, Denmark1001-5000 employeesEsolvitIT services & consulting · Austin, United States51-200 employeesARaymondFastener manufacturers · Grenoble, United States5001-10000 employeesvTech Solution, Inc.SME managed IT services · 201-500 employeesVINCORIONDefence systems manufacturers · Wedel, Germany501-1000 employeesCigna HealthcareHealth insurance brokers · United States10,001+ employeesPTP Inc.Applied AI ML development · Sacramento, United States51-200 employeesBluestoneMortgage & property finance · Haymarket, Australia201-500 employees22nd Century TechnologiesSME managed IT services · United States5001-10000 employeesGeneral MotorsPassenger car & light truck manufacturers · Detroit, United States10,001+ employeesCogent InfotechIT services & consulting · Pittsburgh, United States501-1000 employeesTechnogenIT services & consulting · Lafayette, United States201-500 employeesArete Technologies, Inc.It & tech recruitment · Cary, United States201-500 employeesPACCAROther vehicle & transport equipment manufacturing · Bellevue, United States10,001+ employees
63 companies show IBM Rational; 0 of them have over 1,000 employees.

Filter by country, size, team and source, open verified e-mails for the decision makers, or push new matches to your CRM every week.

Free plan: 1,000 records, no card. The first 20 are above; e-mails are verified at the mail server when you open them.

06 — Job-posting evidence

Who runs IBM Rational inside the company

The 63 companies whose postings name IBM Rational: by country, size and the function of the role. The second number in the function table is companies.

Postings by function
postings · companies
Software engineering
131 · 54
Engineering (non-software)
72 · 19
IT operations & business systems
22 · 18
Product, program & project management
14 · 10
Quality, safety & environment
11 · 5
Data & AI
4 · 3
Administration & office
2 · 2
Sales
2 · 1
Unclassified
2 · 1
General management & consulting
1 · 1
Posting companies by country
companiesshare
United States
4063%
Germany
35%
Austria
12%
Australia
12%
Bulgaria
12%
Brazil
12%
Canada
12%
Czechia
12%
Denmark
12%
United Kingdom
12%
ID
12%
India
12%
Posting companies by size
companiesshare
Self-employed
23%
2-10 employees
23%
11-50 employees
35%
51-200 employees
1422%
201-500 employees
1117%
501-1000 employees
711%
1001-5000 employees
711%
5001-10000 employees
46%
10,001+ employees
1321%
Hiring on it right now
postings
Postings, last 30 days
99
Postings, last 90 days
138
All open postings
286

43 companies opened a role that names IBM Rational in the last 30 days. A hiring team that names its tools is the moment to write to the person who owns the stack.

07 — Named alongside

What IBM Rational teams also ask for

Tools named in the same postings as IBM Rational. Office software is left out.

08 — requirements mbse

IBM Rational against the rest of its category

Ranked by companies naming each tool in postings. Whole category →

Cite this

Quote the sentence with the date and the link. The numbers change daily; the link always shows the current ones.

63 companies name IBM Rational 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/ibm-rational)
How we know

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 IBM Rational 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.
FAQ

IBM Rational data: questions

How many companies use IBM Rational?

63 as of 4 November 2026: 0 carry IBM Rational on their website or in their DNS records and 63 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 IBM Rational'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 IBM Rational. 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 IBM Rational, 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 63 with verified e-mails and a weekly feed of new IBM Rational users is in the product. Counting is free.

Companies and people

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 IBM Rational,
with the person who owns it

Connect the MCP server or the API, filter on IBM Rational, and get 1,000 records free.

  1. 01Sign up, no card
  2. 02Connect Claude, ChatGPT or an API key
  3. 03Ask for your market, 1,000 records free