Tools · backend frameworks

Companies using FastAPI_

As of 4 November 2026, 3,305 companies name FastAPI 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 · 5,700 postings
Hiring on it, last 30 days
2,344 companies
Most often alongside
Amazon Web Services · 2,171 companies
3,305companies show FastAPI, all sources
0on their website or in DNS records
3,305name it in their own job postings
8,205postings naming FastAPI, last 90 days
02 — Two ways we see a tool

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

Job postings3,305

Companies whose own postings say the team works in FastAPI. 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 FastAPI. The rest of the posting population (3,305) runs FastAPI without a public trace on the site or in DNS, which is where job data earns its place.

03 — Who uses it

Companies on FastAPI

Companies with 201+ employees and high-confidence evidence in their own postings; job boards and portals left out.

InfineonSemiconductor manufacturers · United States10,001+ employeesGovernment Technology Agency of Singapore (GovTech Singapore)Government agencies & ministries · Singapore1001-5000 employeesHF MarketsForex cfd brokers · Cape Town, United Kingdom201-500 employeesMicronSemiconductor manufacturers · Boise, United States10,001+ employeesMorgan & Morgan, P.A.Personal injury law · Orlando, United States5001-10000 employeesCook MedicalMedical device manufacturers · Bloomington, United States10,001+ employeesZurich InsuranceInsurance companies underwriters · Zürich, Switzerland1001-5000 employeesArbiAI recruiting talent software · United States501-1000 employeesBCD TravelCorporate travel management companies · United States10,001+ employeesMintelMarket research providers · London, United Kingdom1001-5000 employeesUniversity of HuddersfieldUniversities · Huddersfield, United Kingdom1001-5000 employeesSecurityHQManaged cybersecurity services · United States201-500 employeesSavantaMarket research providers · Glasgow, United Kingdom501-1000 employeesAbbViePharmaceutical manufacturers · United States10,001+ employeesGuidewireWealth insurance advisor software · San Mateo, United States1001-5000 employeesSkechersFootwear webshops · Manhattan Beach, United States10,001+ employeesNIQMarket research providers · Chicago, United States10,001+ employeesDocVu.AIDocument management automation · United States201-500 employeesRBCRetail & commercial banks · United States10,001+ employeesBitdefenderManaged cybersecurity services · Fortaleza, Austria1001-5000 employees
3,305 companies show FastAPI; 0 of them have over 1,000 employees.

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06 — Job-posting evidence

Who runs FastAPI inside the company

The 3,305 companies whose postings name FastAPI: 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
5,700 · 2,556
Data & AI
3,430 · 1,564
IT operations & business systems
272 · 128
Engineering (non-software)
93 · 67
Product, program & project management
58 · 25
Unclassified
30 · 19
Sales
25 · 21
General management & consulting
23 · 16
Marketing & communications
19 · 5
Finance & accounting
13 · 8
Posting companies by country
companiesshare
United States
1,82955%
United Kingdom
2357%
Germany
1795%
India
1735%
France
1184%
Canada
672%
Spain
411%
Poland
411%
Australia
381%
Netherlands
381%
Singapore
371%
Brazil
351%
Posting companies by size
companiesshare
Self-employed
2016%
2-10 employees
54416%
11-50 employees
60318%
51-200 employees
63619%
201-500 employees
34911%
501-1000 employees
2307%
1001-5000 employees
32910%
5001-10000 employees
1073%
10,001+ employees
3069%
Hiring on it right now
postings
Postings, last 30 days
6,187
Postings, last 90 days
8,205
All open postings
10,598

2,344 companies opened a role that names FastAPI 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 FastAPI teams also ask for

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

08 — backend frameworks

FastAPI 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.

3,305 companies name FastAPI 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/fastapi)
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 FastAPI 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

FastAPI data: questions

How many companies use FastAPI?

3,305 as of 4 November 2026: 0 carry FastAPI on their website or in their DNS records and 3,305 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 FastAPI'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 FastAPI. 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 FastAPI, 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 3,305 with verified e-mails and a weekly feed of new FastAPI users is in the product. Counting is free.

Companies and people

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