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 29 March 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
29 Mar 2017
Same period 2016 Same period 2015
Rank 11 12 -
Rank change year-on-year +1 -  
Contract jobs citing TDD 5 1 0
As % of all contract IT jobs advertised in Welwyn Garden City 9.09% 1.72% -
As % of the Processes & Methodologies category 10.20% 3.03% -
Number of daily rates quoted 3 0 0
Median daily rate £500 - -
UK excluding London median daily rate £400 £400 £375
% change year-on-year - +6.66%  
Number of hourly rates quoted 0 0 0
Median hourly rate - - -
UK excluding London median hourly rate £39.00 £45.75 £36.00
% change year-on-year -14.75% +27.08%  

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 49 33 17
As % of all contract IT job vacancies advertised in Welwyn Garden City 89.09% 56.90% 47.22%
Number of daily rates quoted 19 14 4
Median daily rate £475 £425 £375
Median daily rate % change year-on-year +11.76% +13.33%  
90% offered a daily rate of more than £325 £325 £360
10% offered a daily rate of more than £555 £550 £390
UK excluding London median daily rate £410 £400 £396
% change year-on-year +2.50% +1.01%  
Number of hourly rates quoted 2 1 0
Median hourly rate £30.00 £9.23 -
Median hourly rate % change year-on-year +225.02% -  
UK excluding London median hourly rate £35.75 £38.50 £30.00
% change year-on-year -7.14% +28.33%  

TDD
Job Vacancy Trend in Welwyn Garden City

The job posting trend of jobs advertised in Welwyn Garden City citing TDD as a proportion of all contract or permanent IT jobs with a match in the Processes & Methodologies category.

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 29 March 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 12 (80.00%) Agile Software Development
1 12 (80.00%) Git (software)
1 12 (80.00%) BDD
2 11 (73.33%) JIRA
2 11 (73.33%) Java
3 9 (60.00%) OO
3 9 (60.00%) Amazon AWS
3 9 (60.00%) DevOps
4 7 (46.67%) Ansible
4 7 (46.67%) Gradle
4 7 (46.67%) Jenkins
4 7 (46.67%) Opscode Chef
4 7 (46.67%) Data Structures
4 7 (46.67%) Algorithms
4 7 (46.67%) Puppet
4 7 (46.67%) ATDD
4 7 (46.67%) QA
4 7 (46.67%) OOD
4 7 (46.67%) Ant
4 7 (46.67%) Maven
4 7 (46.67%) Complexity Analysis
5 6 (40.00%) Software Engineering
5 6 (40.00%) Retail
5 6 (40.00%) XML
5 6 (40.00%) JavaScript
5 6 (40.00%) Go
6 5 (33.33%) Clojure
6 5 (33.33%) Rust
6 5 (33.33%) JSON
6 5 (33.33%) REST

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 2 (13.33%) CMS
1 2 (13.33%) IIS
1 2 (13.33%) Magnolia
2 1 (6.67%) Apache Spark
2 1 (6.67%) Elasticsearch
2 1 (6.67%) nginx
Applications
1 2 (13.33%) Photoshop
Cloud Services
1 9 (60.00%) Amazon AWS
Communications & Networking
1 2 (13.33%) TCP/IP
Database & Business Intelligence
1 2 (13.33%) Relational Database
1 2 (13.33%) SQL Server
1 2 (13.33%) SQL Server 2012
2 1 (6.67%) Hadoop
2 1 (6.67%) MongoDB
2 1 (6.67%) MySQL
2 1 (6.67%) NoSQL
2 1 (6.67%) Redis
Development Applications
1 12 (80.00%) Git (software)
2 11 (73.33%) JIRA
3 7 (46.67%) Ant
3 7 (46.67%) Gradle
3 7 (46.67%) Jenkins
3 7 (46.67%) Maven
4 2 (13.33%) Atlassian Bamboo
4 2 (13.33%) FxCop
4 2 (13.33%) Grunt
4 2 (13.33%) gulp
4 2 (13.33%) Moq
4 2 (13.33%) ReSharper
4 2 (13.33%) StyleCop
5 1 (6.67%) Vagrant
General
1 6 (40.00%) Retail
Job Titles
1 10 (66.67%) Developer
2 6 (40.00%) Java Developer
3 3 (20.00%) Architect
4 2 (13.33%) .NET Developer
4 2 (13.33%) ASP.NET Developer
4 2 (13.33%) ASP.NET MVC Developer
4 2 (13.33%) AWS Architect
4 2 (13.33%) C# .NET Developer
4 2 (13.33%) C# ASP.NET Developer
4 2 (13.33%) C# Developer
4 2 (13.33%) Front End Developer (Client-Side Developer)
4 2 (13.33%) Java Architect
4 2 (13.33%) Java Engineer
4 2 (13.33%) JavaScript Developer
4 2 (13.33%) Lead Developer
4 2 (13.33%) Lead Java Developer
5 1 (6.67%) Cloud Developer
5 1 (6.67%) Java Scala Developer
5 1 (6.67%) Scala Developer
5 1 (6.67%) Web UI Developer
Libraries, Frameworks & Software Standards
1 6 (40.00%) XML
2 5 (33.33%) CSS
2 5 (33.33%) HTML
2 5 (33.33%) JSON
2 5 (33.33%) REST
3 3 (20.00%) Spring
4 2 (13.33%) .NET
4 2 (13.33%) .NET Framework
4 2 (13.33%) ADO.NET
4 2 (13.33%) Ajax
4 2 (13.33%) AngularJS
4 2 (13.33%) ASP.NET
4 2 (13.33%) AutoMapper
4 2 (13.33%) CSS3
4 2 (13.33%) NHibernate
4 2 (13.33%) Sass
4 2 (13.33%) SOAP
4 2 (13.33%) XHTML
4 2 (13.33%) XSL
4 2 (13.33%) XSLT
Miscellaneous
1 7 (46.67%) Algorithms
1 7 (46.67%) Data Structures
2 2 (13.33%) Contactless
2 2 (13.33%) EMV
2 2 (13.33%) FMCG
2 2 (13.33%) iPad
2 2 (13.33%) User Experience
2 2 (13.33%) W3C
Operating Systems
1 1 (6.67%) Linux
Processes & Methodologies
1 12 (80.00%) Agile Software Development
1 12 (80.00%) BDD
2 9 (60.00%) DevOps
2 9 (60.00%) OO
3 7 (46.67%) ATDD
3 7 (46.67%) Complexity Analysis
3 7 (46.67%) OOD
4 6 (40.00%) Software Engineering
5 4 (26.67%) E-Commerce
5 4 (26.67%) Refactoring
5 4 (26.67%) SOLID
6 3 (20.00%) Microservices
6 3 (20.00%) MVC
6 3 (20.00%) Web Development
7 2 (13.33%) API Development
7 2 (13.33%) Continuous Delivery
7 2 (13.33%) Front End Development
7 2 (13.33%) Open Source
7 2 (13.33%) Responsive Web Design
7 2 (13.33%) Unit Testing
Programming Languages
1 11 (73.33%) Java
2 6 (40.00%) Go
2 6 (40.00%) JavaScript
3 5 (33.33%) Clojure
3 5 (33.33%) Rust
4 4 (26.67%) C#
5 3 (20.00%) F#
6 2 (13.33%) VBScript
7 1 (6.67%) C++
7 1 (6.67%) Lua
7 1 (6.67%) Python
7 1 (6.67%) Scala
7 1 (6.67%) SQL
Quality Assurance & Compliance
1 7 (46.67%) QA
2 2 (13.33%) WAI
System Software
1 1 (6.67%) Docker
Systems Management
1 7 (46.67%) Ansible
1 7 (46.67%) Opscode Chef
1 7 (46.67%) Puppet
2 2 (13.33%) TeamSite
Vendors
1 2 (13.33%) Atlassian