The following table provides summary statistics for contract job vacancies advertised in Welwyn Garden City with a requirement for TDD skills. Included is a benchmarking guide to the contractor rates offered in vacancies that have cited TDD over the 3 months to 28 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.

Test-Driven Development (TDD)
Hertfordshire / Welwyn Garden City
3 months to
28 Jun 2017
Same period 2016 Same period 2015
Rank 11 16 22
Rank change year-on-year +5 +6  
Contract jobs citing TDD 2 1 1
As % of all contract IT jobs advertised in Welwyn Garden City 3.57% 1.52% 0.80%
As % of the Processes & Methodologies category 4.35% 1.89% 0.94%
Number of daily rates quoted 2 1 1
Median daily rate £500 £430 £550
Median daily rate % change year-on-year +16.27% -21.81%  
90% offered a daily rate of more than £445 £430 £535
10% offered a daily rate of more than £535 £430 £565
UK excluding London median daily rate £420 £413 £375
% change year-on-year +1.81% +10.00%  
Number of hourly rates quoted 0 0 0
Median hourly rate - - -
UK excluding London median hourly rate £41.50 £40.00 £43.75
% change year-on-year +3.75% -8.57%  

TDD is in the process and methodology skills category. The next table is for comparison with the above and provides summary statistics for all contract job vacancies advertised in Welwyn Garden City with a requirement for process and methodology skills.

Contract Process & Methodology Skills
Welwyn Garden City
Contract job vacancies with a requirement for process and methodology skills 46 53 106
As % of all contract IT job vacancies advertised in Welwyn Garden City 82.14% 80.30% 84.80%
Number of daily rates quoted 104 94 157
Median daily rate £475 £408 £310
Median daily rate % change year-on-year +16.56% +31.45%  
90% offered a daily rate of more than £170 £281 £200
10% offered a daily rate of more than £588 £438 £377
UK excluding London median daily rate £415 £400 £380
% change year-on-year +3.75% +5.26%  
Number of hourly rates quoted 3 4 2
Median hourly rate £13.00 £18.25 £47.50
Median hourly rate % change year-on-year -28.76% -61.57%  
UK excluding London median hourly rate £34.00 £28.50 £30.00
% change year-on-year +19.29% -5.00%  

TDD
Job Vacancy Trend in Welwyn Garden City

Job postings citing TDD as a percentage of all IT jobs advertised in Welwyn Garden City.

Job vacancy trend for TDD in Welwyn Garden City

TDD
Contractor Daily Rate Trend in Welwyn Garden City

This chart provides the 3-month moving average for daily rates quoted in contract jobs citing TDD in Welwyn Garden City.

Contractor daily rate trend for TDD in Welwyn Garden City

For the 6 months to 28 June 2017, IT contractor jobs citing TDD 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 Welwyn Garden City region with a requirement for TDD.

1 5 (71.43%) XML
1 5 (71.43%) Agile Software Development
1 5 (71.43%) JSON
1 5 (71.43%) BDD
2 4 (57.14%) Git (software)
2 4 (57.14%) DevOps
2 4 (57.14%) JIRA
2 4 (57.14%) Java
3 3 (42.86%) JavaScript
3 3 (42.86%) Photoshop
3 3 (42.86%) CSS
3 3 (42.86%) XHTML
3 3 (42.86%) E-Commerce
3 3 (42.86%) TeamSite
3 3 (42.86%) W3C
3 3 (42.86%) Project Management
3 3 (42.86%) SEO
3 3 (42.86%) Stakeholder Management
3 3 (42.86%) CMS
3 3 (42.86%) Web Design
3 3 (42.86%) Retail
3 3 (42.86%) Spring
3 3 (42.86%) Ajax
3 3 (42.86%) Web Development
3 3 (42.86%) WAI
3 3 (42.86%) User Experience
3 3 (42.86%) Microservices
3 3 (42.86%) Grunt
3 3 (42.86%) Magnolia
3 3 (42.86%) Node.js

TDD
Co-occurring IT Skills in Welwyn Garden City 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 3 (42.86%) CMS
1 3 (42.86%) Magnolia
Applications
1 3 (42.86%) Photoshop
Cloud Services
1 3 (42.86%) Amazon AWS
Development Applications
1 4 (57.14%) Git (software)
1 4 (57.14%) JIRA
2 3 (42.86%) Grunt
2 3 (42.86%) gulp
3 1 (14.29%) Ant
3 1 (14.29%) Gradle
3 1 (14.29%) Jenkins
3 1 (14.29%) Maven
General
1 3 (42.86%) Retail
Job Titles
1 4 (57.14%) Developer
2 3 (42.86%) Front End Developer (Client-Side Developer)
3 2 (28.57%) Architect
3 2 (28.57%) AWS Architect
3 2 (28.57%) Java Architect
4 1 (14.29%) Front End Web Developer (Client-Side Developer)
4 1 (14.29%) Java Developer
4 1 (14.29%) Java Engineer
4 1 (14.29%) JavaScript Developer
4 1 (14.29%) UI Developer
4 1 (14.29%) Web Developer
4 1 (14.29%) Web UI Developer
Libraries, Frameworks & Software Standards
1 5 (71.43%) JSON
1 5 (71.43%) XML
2 3 (42.86%) Ajax
2 3 (42.86%) AngularJS
2 3 (42.86%) CSS
2 3 (42.86%) CSS3
2 3 (42.86%) HTML
2 3 (42.86%) HTML5
2 3 (42.86%) jQuery
2 3 (42.86%) Node.js
2 3 (42.86%) React
2 3 (42.86%) Sass
2 3 (42.86%) Spring
2 3 (42.86%) XHTML
3 2 (28.57%) REST
3 2 (28.57%) Spring Boot
4 1 (14.29%) Hibernate
4 1 (14.29%) RESTful
4 1 (14.29%) Web Services
Miscellaneous
1 3 (42.86%) User Experience
1 3 (42.86%) W3C
2 2 (28.57%) iPad
3 1 (14.29%) Algorithms
3 1 (14.29%) Data Structures
Processes & Methodologies
1 5 (71.43%) Agile Software Development
1 5 (71.43%) BDD
2 4 (57.14%) DevOps
3 3 (42.86%) A/B Testing
3 3 (42.86%) API Development
3 3 (42.86%) E-Commerce
3 3 (42.86%) Front End Development
3 3 (42.86%) Microservices
3 3 (42.86%) Project Management
3 3 (42.86%) Responsive Web Design
3 3 (42.86%) SEO
3 3 (42.86%) Stakeholder Management
3 3 (42.86%) Unit Testing
3 3 (42.86%) Web Design
3 3 (42.86%) Web Development
3 3 (42.86%) Wireframes
4 2 (28.57%) Continuous Delivery
4 2 (28.57%) Open Source
4 2 (28.57%) Refactoring
4 2 (28.57%) SOLID
Programming Languages
1 4 (57.14%) Java
2 3 (42.86%) JavaScript
3 1 (14.29%) Clojure
3 1 (14.29%) F#
3 1 (14.29%) Go
3 1 (14.29%) Rust
3 1 (14.29%) Scala
Quality Assurance & Compliance
1 3 (42.86%) WAI
2 1 (14.29%) QA
Systems Management
1 3 (42.86%) TeamSite
2 1 (14.29%) Ansible
2 1 (14.29%) Opscode Chef
2 1 (14.29%) Puppet