Who uses Clojure
Over 175 companies have actively advertised their Clojure adoption, and given the broad participation in user groups there are clearly many more organizations using Clojure at some level in their technology stack.
A quick scan of various job sites shows Clojure positions at companies like Walmart, Facebook, Staples, Consumer Reports, Salesforce, and Amazon. It doesn't get much more mainstream than that.
If you are looking for a new role using Clojure or other functional programming languages, visit Functional Works, the only Functional Recruiters in the world.
Here is just a small and diverse set of example companies that I am aware of that use Clojure for development.
|Company||Type of applications|
|Boeing||Boeing 737 MAX - onboard maintainance|
|Puppet Labs||DevOps apps & services eg. trapperkeeper|
|Cisco||Malware analysis & threat intelligence platform (expert system with core.logic)|
|Deuche Bank (UK)||Processing event streams from Apache Storm|
|Atlassian||Collaborative editing platform for all their products|
|Netflix||Map-Reduce languages for writing apps for Hadoop / Pig|
|USwitch (UK)||Creating meaningful data from multiple sources|
|Daily Mail Online (UK)||Publishing pipeline|
|Circle CI (USA)||Frontend of CI server in Clojurescript & test suite|
|Student Loans company (UK)||Loans management system written in Clojure|
|Powers the LinkedIn social graph|
|Walmart (USA)||eReceipts project to process every purchase from 5,000+ stores|
|SwiftKey (UK)||Predictive intelligence platform (possibly used with Microsoft Cortana)|
|Roomkey.co.uk||Hotel booking system to rival Expedia (with a tiny development team)|
|Funding Circle (UK & USA)||Adopting Clojure as their main language (from Ruby, etc)|
|Braintree||Payment processing pipeline with Kafka|
|Mastodon C||Data centre analysis (Incanta, Storm)|
|Thoughtworks||Agile development for Client projects world wide|
|Vero Insurance (AUS)||Rebuilt policy management system in Clojure with Thoughworks|
|Meta-X||Performance art (Overtone, Quil)|
|Salesforce (USA)||Build & deployment with Puppet & Application Routing with nginx-clojure|
There are many more examples of projects on the HackerNews thread: Ask HN: Who's using Clojure in Production
Clojure is also defined as a technology that can be adopted since 2014, according to the Thoughtworks technology radar.
JUXT also created its own Clojure specific technology radar as there is such an encompasing ecosystem of libraries and services.