The following table provides summary statistics for contract job vacancies advertised in the City of London with a requirement for CentOS skills. Included is a benchmarking guide to the contractor rates offered in vacancies that have cited CentOS over the 3 months to 25 June 2017 with a comparison to the same period in the previous 2 years.

Note that daily and hourly rates are treated separately in these statistics. When calculating contractor rate percentiles, daily rates are never derived from quoted hourly rates or vice versa.

CentOS Linux
London / City of London
3 months to
25 Jun 2017
Same period 2016 Same period 2015
Rank 147 155 189
Rank change year-on-year +8 +34  
Contract jobs citing CentOS 16 11 13
As % of all contract IT jobs advertised in the City of London 0.49% 0.33% 0.22%
As % of the Operating Systems category 2.47% 1.52% 1.11%
Number of daily rates quoted 15 8 12
Median daily rate £475 £475 £413
Median daily rate % change year-on-year - +15.15%  
90% offered a daily rate of more than £330 £418 £363
10% offered a daily rate of more than £525 £533 £549
UK excluding London median daily rate £460 £425 £375
% change year-on-year +8.23% +13.33%  
Number of hourly rates quoted 0 0 0
Median hourly rate - - -
UK excluding London median hourly rate £47.50 £55.00 -
% change year-on-year -13.63% -  

CentOS is in the operating system skills category. The next table is for comparison with the above and provides summary statistics for all contract job vacancies advertised in the City of London with a requirement for operating system skills.

Contract Operating System Skills
City of London
Contract job vacancies with a requirement for operating system skills 648 724 1172
As % of all contract IT job vacancies advertised in the City of London 19.79% 21.79% 20.13%
Number of daily rates quoted 509 601 901
Median daily rate £450 £463 £400
Median daily rate % change year-on-year -2.70% +15.62%  
90% offered a daily rate of more than £220 £250 £225
10% offered a daily rate of more than £623 £600 £575
UK excluding London median daily rate £375 £363 £345
% change year-on-year +3.44% +5.07%  
Number of hourly rates quoted 18 21 54
Median hourly rate £21.25 £17.50 £20.00
Median hourly rate % change year-on-year +21.42% -12.50%  
90% offered a hourly rate of more than £14.98 £12.50 £12.50
10% offered a hourly rate of more than £175.00 £22.00 £34.00
UK excluding London median hourly rate £15.50 £17.00 £16.20
% change year-on-year -8.82% +4.93%  

CentOS
Job Vacancy Trend in the City of London

The job posting trend of jobs advertised in the City of London citing CentOS as a proportion of all contract or permanent IT jobs with a match in the Operating Systems category.

Job vacancy trend for CentOS in the City of London

CentOS
Contractor Daily Rate Trend in the City of London

This chart provides the 3-month moving average for daily rates quoted in contract jobs citing CentOS in the City of London.

Contractor daily rate trend for CentOS in the City of London

CentOS
Contractor Daily Rate Histogram in the City of London

The daily rate distribution of IT jobs citing CentOS in the City of London over the 3 months to 25 June 2017.

Contractor daily rate histogram for CentOS in the City of London

For the 6 months to 25 June 2017, IT contractor jobs citing CentOS also mentioned the following skills in order of popularity. The figures indicate the number co-occurrences and its proportion to all contract ads across the City of London region with a requirement for CentOS.

1 44 (100.00%) Linux
2 30 (68.18%) Python
3 20 (45.45%) Perl
3 20 (45.45%) Bash Shell
4 19 (43.18%) DevOps
5 17 (38.64%) Amazon AWS
5 17 (38.64%) Java
6 16 (36.36%) Puppet
7 15 (34.09%) Red Hat
7 15 (34.09%) Ruby
8 14 (31.82%) Red Hat Enterprise Linux
9 12 (27.27%) Ubuntu
9 12 (27.27%) VMware
10 11 (25.00%) Windows
10 11 (25.00%) Git (software)
10 11 (25.00%) Jenkins
10 11 (25.00%) Ansible
10 11 (25.00%) Docker
11 9 (20.45%) VMware Infrastructure
11 9 (20.45%) MySQL
12 8 (18.18%) SAN
12 8 (18.18%) TCP/IP
12 8 (18.18%) Finance
13 7 (15.91%) Telecoms
13 7 (15.91%) Agile Software Development
13 7 (15.91%) DNS
13 7 (15.91%) Project Management
13 7 (15.91%) C
13 7 (15.91%) Security Cleared
13 7 (15.91%) Kubernetes

CentOS
Co-occurring IT Skills in the City of London by Category

The follow tables expand on the table above by listing co-occurrences grouped by category. The same job type, locality and period is covered with up to 20 co-occurrences shown in each of the following categories:

Application Platforms
1 5 (11.36%) Tomcat
2 4 (9.09%) Jetty
2 4 (9.09%) nginx
3 2 (4.55%) Apache
3 2 (4.55%) CMS
3 2 (4.55%) IIS
3 2 (4.55%) OpenStack
4 1 (2.27%) Apache Solr
4 1 (2.27%) Confluence
4 1 (2.27%) Elasticsearch
Cloud Services
1 17 (38.64%) Amazon AWS
2 4 (9.09%) Cloud Computing
3 3 (6.82%) Microsoft Azure
4 2 (4.55%) AWS CloudFormation
4 2 (4.55%) AWS Lambda
4 2 (4.55%) SaaS
5 1 (2.27%) Amazon EC2
5 1 (2.27%) Amazon Kinesis
5 1 (2.27%) Amazon SQS
5 1 (2.27%) Bluemix
5 1 (2.27%) GitHub
5 1 (2.27%) Google Cloud Platform
5 1 (2.27%) Google Compute Engine
5 1 (2.27%) IaaS
5 1 (2.27%) IBM Cloud
5 1 (2.27%) Office 365
Communications & Networking
1 8 (18.18%) SAN
1 8 (18.18%) TCP/IP
2 7 (15.91%) DNS
3 5 (11.36%) DHCP
3 5 (11.36%) NAS
3 5 (11.36%) SMTP
4 2 (4.55%) HTTP
4 2 (4.55%) LDAP
4 2 (4.55%) Wi-Fi
5 1 (2.27%) Fibre Channel
5 1 (2.27%) iSCSI
5 1 (2.27%) Kerberos
5 1 (2.27%) SSL
Database & Business Intelligence
1 9 (20.45%) MySQL
2 5 (11.36%) SQL Server
3 4 (9.09%) MongoDB
3 4 (9.09%) NoSQL
4 3 (6.82%) Apache Hive
4 3 (6.82%) Big Data
4 3 (6.82%) Hadoop
4 3 (6.82%) PostgreSQL
5 2 (4.55%) Amazon DynamoDB
5 2 (4.55%) Apache Cassandra
5 2 (4.55%) InterSystems Cache
5 2 (4.55%) MariaDB
6 1 (2.27%) HBase
6 1 (2.27%) Impala
6 1 (2.27%) Relational Database
Development Applications
1 11 (25.00%) Git (software)
1 11 (25.00%) Jenkins
2 3 (6.82%) Maven
2 3 (6.82%) Team Foundation Server
2 3 (6.82%) TeamCity
3 2 (4.55%) Atlassian Bamboo
4 1 (2.27%) Bitbucket
4 1 (2.27%) GoCD
4 1 (2.27%) JIRA
4 1 (2.27%) Talend Open Studio
4 1 (2.27%) Vagrant
General
1 8 (18.18%) Finance
2 7 (15.91%) Telecoms
3 1 (2.27%) Banking
3 1 (2.27%) Games
3 1 (2.27%) Investment Banking
3 1 (2.27%) Law
Job Titles
1 16 (36.36%) DevOps Engineer
2 9 (20.45%) Developer
3 7 (15.91%) Linux Engineer
4 6 (13.64%) Administrator
5 5 (11.36%) Linux DevOps Engineer
5 5 (11.36%) Linux/Unix DevOps
6 4 (9.09%) Analyst
6 4 (9.09%) DBA
6 4 (9.09%) Unix Analyst
6 4 (9.09%) Unix Support
7 3 (6.82%) C++ Developer
7 3 (6.82%) Java Engineer
7 3 (6.82%) Support Analyst
7 3 (6.82%) Systems Administrator
7 3 (6.82%) Unix Support Analyst
8 2 (4.55%) Big Data Engineer
8 2 (4.55%) C/C++ Developer
8 2 (4.55%) Data Engineer
8 2 (4.55%) Hadoop Engineer
8 2 (4.55%) Infrastructure Support
Libraries, Frameworks & Software Standards
1 5 (11.36%) HTML
1 5 (11.36%) Web Services
2 4 (9.09%) LAMP
2 4 (9.09%) LEMP Stack
2 4 (9.09%) Servlets
3 3 (6.82%) .NET
3 3 (6.82%) ASP.NET
3 3 (6.82%) ASP.NET MVC
3 3 (6.82%) ASP.NET MVC 4
3 3 (6.82%) Boost C++ Libraries
3 3 (6.82%) CSS
3 3 (6.82%) JSON
3 3 (6.82%) RESTful
3 3 (6.82%) RSS
3 3 (6.82%) SignalR
3 3 (6.82%) XML
3 3 (6.82%) XSLT
4 2 (4.55%) HTML5
4 2 (4.55%) jQuery
4 2 (4.55%) LINQ
Miscellaneous
1 4 (9.09%) Analytical Skills
1 4 (9.09%) Computer Science
1 4 (9.09%) User Experience
2 3 (6.82%) Web 2.0
3 2 (4.55%) Clustering
3 2 (4.55%) CMDB
3 2 (4.55%) Data Centre
3 2 (4.55%) Enterprise Storage
3 2 (4.55%) Greenfield Project
3 2 (4.55%) Management Information System
4 1 (2.27%) Derivative
4 1 (2.27%) Fintech
4 1 (2.27%) Mobile App
4 1 (2.27%) Private Cloud
4 1 (2.27%) Replication
Operating Systems
1 44 (100.00%) Linux
2 14 (31.82%) Red Hat Enterprise Linux
3 12 (27.27%) Ubuntu
4 11 (25.00%) Windows
5 5 (11.36%) Solaris
5 5 (11.36%) Unix
5 5 (11.36%) Windows Server
6 2 (4.55%) Data ONTAP
7 1 (2.27%) Fedora
7 1 (2.27%) SUSE
Processes & Methodologies
1 19 (43.18%) DevOps
2 7 (15.91%) Agile Software Development
2 7 (15.91%) Project Management
3 6 (13.64%) Configuration Management
3 6 (13.64%) High Availability
4 5 (11.36%) Continuous Delivery
4 5 (11.36%) OOP
5 4 (9.09%) Capacity Planning
5 4 (9.09%) Low Latency
5 4 (9.09%) OO
5 4 (9.09%) Patch Management
5 4 (9.09%) Performance Monitoring
5 4 (9.09%) Performance Tuning
5 4 (9.09%) Release Management
5 4 (9.09%) Server Building
5 4 (9.09%) System Testing
6 3 (6.82%) Analytics
6 3 (6.82%) API Design
6 3 (6.82%) Responsive Web Design
6 3 (6.82%) SDLC
Programming Languages
1 30 (68.18%) Python
2 20 (45.45%) Bash Shell
2 20 (45.45%) Perl
3 17 (38.64%) Java
4 15 (34.09%) Ruby
5 7 (15.91%) C
6 5 (11.36%) Korn
6 5 (11.36%) PowerShell
6 5 (11.36%) Shell Script
7 4 (9.09%) C++
7 4 (9.09%) JavaScript
8 3 (6.82%) C#
8 3 (6.82%) PHP
9 2 (4.55%) CQL
9 2 (4.55%) Go
Qualifications
1 7 (15.91%) Security Cleared
2 6 (13.64%) SC Cleared
3 4 (9.09%) Degree
4 3 (6.82%) Computer Science Degree
Quality Assurance & Compliance
1 2 (4.55%) QA
System Software
1 11 (25.00%) Docker
2 9 (20.45%) VMware Infrastructure
3 5 (11.36%) Hyper-V
4 2 (4.55%) Active Directory
5 1 (2.27%) Apache ZooKeeper
5 1 (2.27%) HDFS
5 1 (2.27%) NFS
5 1 (2.27%) Virtual Machines
Systems Management
1 16 (36.36%) Puppet
2 11 (25.00%) Ansible
3 7 (15.91%) Kubernetes
3 7 (15.91%) Terraform
4 5 (11.36%) Opscode Chef
5 4 (9.09%) Cobbler
5 4 (9.09%) Nagios
5 4 (9.09%) Packer
5 4 (9.09%) Red Hat Spacewalk
5 4 (9.09%) Salt
6 3 (6.82%) IBM BigFix
6 3 (6.82%) Mesos
6 3 (6.82%) TADDM
7 2 (4.55%) Marathon
7 2 (4.55%) NetBackup
8 1 (2.27%) Graphite
8 1 (2.27%) Hadoop YARN
8 1 (2.27%) Kibana
8 1 (2.27%) Prometheus
8 1 (2.27%) vCenter Server
Vendors
1 15 (34.09%) Red Hat
2 12 (27.27%) VMware
3 6 (13.64%) EMC
3 6 (13.64%) NetApp
4 4 (9.09%) Cisco
5 3 (6.82%) IBM
5 3 (6.82%) ServiceNow
6 2 (4.55%) OpenText
6 2 (4.55%) Oracle
6 2 (4.55%) RedDot
6 2 (4.55%) Sybase
7 1 (2.27%) Alteryx
7 1 (2.27%) AppDynamics
7 1 (2.27%) Atlassian
7 1 (2.27%) Cloudera
7 1 (2.27%) CommVault
7 1 (2.27%) Google
7 1 (2.27%) PagerDuty
7 1 (2.27%) Tableau
7 1 (2.27%) Talend