Senior Front End Developer (Experimentation)

HM Revenue and Customs

Apply before 11:55 pm on Sunday 27th September 2020


Reference number



£37,503 - £41,683


Senior Executive Officer

Contract type


Business area

HMRC - CDIO - Strategy, Design Architecture and Innovation

Type of role

Information Technology

Working pattern

Flexible working, Full-time, Job share, Part-time

Number of posts



Newcastle Upon Tyne, Manchester, Shipley moving to Leeds Regional Centre, Telford, Worthing

About the job


HMRC is one of the largest organisations in the UK and we own the biggest digital operation in Government. CDIO (Chief Digital Information Office) is our digital business, which runs the IT behind tax and benefits services for 45 million individual and 4.9 million business customers.

We are undergoing a major transformation programme, which includes a £200 million investment in digitisation, so customers can do more for themselves online and in real time, on computers, tablets and smartphones. As a government organisation we need to ensure our services are accessible to everyone. The frontend code ensures that customers can successfully interact with our services, and helps people with disabilities to access the same information, perform the same tasks, and receive the same services by using technology.

We are looking for a frontend developer who will specialise in building production ready A/B tests (experiments). You will be a key figure in supporting HMRC to run more experiments that enable teams to optimise digital services that better meet both user and business needs.

Job description

As a Senior front-end developer specialising in Experimentation (A/B and multivariate testing) you will be integral to our experimentation team and work closely with talented user researchers, designers, performance analysts, developers and product managers.
Utilising front end technologies (JavaScript, HTML, CSS) you will develop good quality A/B tests based on hypotheses and design concepts.
You will apply lean development techniques to build “minimum viable experiments” that help teams quickly learn and iterate their product strategy and design


The core responsibilities for this role include:

• Development of user facing features to run A/B tests for production services using front end technologies (HTML ,CSS, JavaScript)

• Ensure technical feasibility of UI/UX designs

• Provide support and guidance to digital teams with building and running of A/B tests using Optimizely

• Ensure set up and integration of Optimizely and Google analytics for A/B test data analysis

• Evangelise experimentation within HMRC and the development community

Essential skills:

Specialist skills and experience required:

• Proficient in coding in JavaScript, HTML and CSS

• Knowledge of frontend architecture

• Able to code quickly and creatively to build production ready a/b tests that adhere to cross-browser/device standards

• Experience of building A/B tests using A/B testing technologies (Optimizely, Maxymiser, VWO or similar tools)

• Experience of working with pattern libraries

• Understanding of digital optimisation / hypothesis driven design

• Understanding of digital analytics

• Understanding of user centred design and user research

• Proficient understanding of cross-browser compatibility issues and ways to work around them

• Passionate about working at a fast pace and delivering improved user experience and business outcomes

• Knowledge of accessibility, including familiarity with common assistive technology software and technology

Desirable skills:

• Experience on UK Government Design Service (GDS) guidelines and assessments

• Proficient understanding of code versioning tools, such as Git

• Proficient Understanding of WCAG 2.1

• Proficient understanding of W3C standards-compliant code, including HTML and CSS

• Previous work in a Scala/Play environment, particularly with Twirl

• Knowledge of working with JavaScript API’s

Technical skills

We'll assess you against these technical skills during the selection process:

  • Proficient in coding in JavaScript, HTML and CSS
  • Knowledge of frontend architecture
  • Experience of building A/B tests using A/B testing technologies (Optimizely, Maxymiser, VWO or similar tools)
  • Able to code quickly and creatively to build production ready a/b tests that adhere to cross-browser/device standards
  • Understanding of digital optimisation / hypothesis driven design
  • Understanding of digital analytics
  • Understanding of user centred design and user research


• Learning and development tailored to your role
• An environment with flexible working options
• A culture encouraging inclusion and diversity
• A Civil Service pension

If you are applying for a role in an office within a regional center location or a transitional or specialist site, then the following may apply: Daily Travel Assistance will be available for this role, provided the successful applicant is a current HMRC employee and meets the eligibility requirements outlined in the department’s Daily Travel Assistance guidance.

Please also find attached 'Your little extras booklet' for further information.

Things you need to know


Successful candidates must pass a disclosure and barring security check.
People working with government assets must complete basic personnel security standard checks.

Selection process details

This vacancy is using Success Profiles, and will assess your Experience and Technical skills.
Sift and interview dates to be confirmed.

This vacancy is using Success Profiles, and will assess your technical skills and experience

• Your CV
• Your employment history
• A personal statement, which should demonstrate how you meet the essential skills ensuring you give examples relating to your professional experience referring to the essential and desirable criteria above (1000 words max).

An initial sift based on technical experience, skills and your supporting statement may be held if a large number of applications are received.

We will ask you to complete a technical exercise for the interview; further details of this will be included with the invitation to interview. During the interview we will also ask questions that let you demonstrate your experience and technical skills relevant to the role.

Feedback will only be provided if you attend an interview or assessment.

The Interview will be held Online.

Security Update

If you are successful and transferring from another Government Department, we will carry out a check of your identity, nationality, and immigration status (including the right to work in the UK) and a criminal record check before confirming your appointment.

Successful candidates must pass a Disclosure and Barring Security Check. Please note that HMRC have an exemption under the Rehabilitation of Offenders Act 1974, which enables us to make enquiries about both unspent and spent convictions.

In order to process applications without delay, we will be sending a Criminal Record Check to Disclosure and Barring Service on your behalf. However, we recognise in exceptional circumstance some candidates will want to send their completed forms direct. If you will be doing this, please advise Government Recruitment Service of your intention by emailing stating the job reference number in the subject heading.

Applicants who are successful at interview will be, as part of pre-employment screening subject to a check on the Internal Fraud Database (IFD). This check will provide information about employees who have been dismissed for fraud or dishonesty offences. This check also applies to employees who resign or otherwise leave before being dismissed for fraud or dishonesty had their employment continued. Any applicant’s details held on the IFD will be refused employment.

A candidate is not eligible to apply for a role within the Civil Service if the application is made within a 5 year period following a dismissal for carrying out internal fraud against government.

HMRC transformation

HM Revenue and Customs is currently going through an exciting ten-year transformation programme to create a tax authority fit for the future. As part of this, we are committed to providing high-quality jobs and giving employees a great place to work, whichever location you work from.

HM Revenue and Customs has made significant progress with its plans to locate in 13 large, modern, flexible offices, equipped with high-speed digital infrastructure supporting improved customer service and compliance activity. These collaborative workspaces will enable smarter working and great training and development facilities, allowing for the sharing of expertise, local training, promotion, and provide great ongoing career development opportunities.

These offices will be located in central locations in the following towns and cities close to accessible transport links: Glasgow, Edinburgh, Belfast, Newcastle, Leeds, Liverpool, Manchester, Nottingham, Birmingham, Bristol, Cardiff, Croydon and Stratford. Our Regional Centres in Croydon, Bristol and Belfast are already operational.

In addition, there will also be a small number of specialist sites where the work cannot be done anywhere else, in Gartcosh (near Glasgow), Telford, Ipswich, Worthing and Dover, as well as our headquarters in central London. What’s more, our Welsh language service has people located in Porthmadog, as well as Cardiff.

We are letting you know about our future plans because if you are recruited into an office that is not one of these locations, you will be expected, subject to HM Revenue and Customs applicable policies, to move to one of these locations in the future. In some cases, this will be via one of our nine transitional sites.

If you are not a current civil servant, you will not be eligible for financial assistance for your move to the regional centre or a transitional or specialist site.

If you are a current HM Revenue and Customs employee and you joined us through an advert that was advertised on or after 11/01/2017, you will not be eligible for financial assistance for your move to a regional centre, a transitional site or a specialist one. This is in line with the terms of your original appointment to HM Revenue and Customs.

For more information please contact the vacancy holder.

Terms and Conditions

Some of HMRC Terms and Conditions of employment changed on 1st May 2013, these will apply to people who are new recruits to HMRC or who take a new job in HMRC on promotion. The document attached to this advertisement provides more information on the changes we made, please note this is not a full list of HMRC's terms and conditions. If you need to discuss how these changes might affect you, please contact the vacancy holder. For further information on terms and conditions please visit


If you are currently working for an OGD and would like to consider the impact on your pay when joining HMRC, please see the attached document "Pay on Transfer from OGD" for further information.

HMRC is currently negotiating with departmental trade unions to modify its current pay structure, terms and conditions. Those terms are yet to be agreed but when implemented, we envisage that they will be backdated to 1 June 2020. The pay ranges, terms and conditions advertised will be altered by the new deal (subject to collective agreement) and will apply to candidates who are successful for the role.

New entrants are expected to join on the minimum of the pay band.

Further Information

Customer facing roles in HMRC require the ability to converse at ease with members of the public and provide advice in accurate spoken English and/or Welsh where required. Where this is an essential requirement this will be tested as part of the selection process.

Any move to HMRC will mean you will no longer be able to carry on claiming childcare vouchers. You will however have access to the governments Tax Free Childcare scheme.

Reasonable adjustment

If a person with disabilities is put at a substantial disadvantage compared to a non-disabled person, we have a duty to make reasonable changes to our processes.

If you need a change to be made so that you can make your application, you should:
Contact Government Recruitment Service via as soon as possible before the closing date to discuss your needs.

Complete the “Assistance required” section in the “Additional requirements” page of your application form to tell us what changes or help you might need further on in the recruitment process. For instance, you may need wheelchair access at interview, or if you’re deaf, a Language Service Professional.

Feedback will only be provided if you attend an interview or assessment.

Nationality requirements

Open to UK, Commonwealth and European Economic Area (EEA) and certain non EEA nationals. Further information on whether you are able to apply is available here.

Working for the Civil Service

The Civil Service Code sets out the standards of behaviour expected of civil servants.

We recruit by merit on the basis of fair and open competition, as outlined in the Civil Service Commission's recruitment principles.
The Civil Service embraces diversity and promotes equal opportunities. As such, we run a Disability Confident Scheme (DCS) for candidates with disabilities who meet the minimum selection criteria.

Apply and further information

Once this job has closed, the job advert will no longer be available. You may want to save a copy for your records.

Contact point for applicants

Job contact :
Name :  Becky Dominick
Email :
Recruitment team :
Email :

Further information

Appointment to the Civil Service is governed by the Civil Service Commission’s Recruitment Principles. You have the right to complain if you feel a department has breached the requirement of the Recruitment Principles. In the first instance, you should raise the matter directly with the department concerned via If you are not satisfied with the response, you may bring your complaint to the Commission. For further information on bringing a complaint to the Civil Service Commission please visit their web pages:

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