To design, build and deploy AI-powered workflow solutions on the ServiceNow platform, with specialist depth in NowAssist wit Takes agreed requirements and process design through to working, tested, supportable configuration, making the technical decisions that determine whether a solution scales, performs and can be maintained. Acts as the senior technical voice in the Workflow Development team, setting build standards, guiding less experienced developers, and advising on what the platform can and cannot sensibly do.

This is a 12 months Fixed Term Contract Role, if you are interested for Fixed Term Contract then only apply.

What You Will Do:

Operating within the Services function, as part of a new Workflow Development team, the Senior ServiceNow Developer's most important duties and responsibilities include:

Designing and building solutions across the ServiceNow platform, with particular focus on NowAssist capabilities (generative AI skills, AI agents, Virtual Agent, AI Search).
Configuring and tuning NowAssist skills — including prompt design, grounding against the right data sources, and evaluating output quality before release.
Building and extending TPSM capability, including case management, install base and product catalogue, entitlements, order management and Service Bridge integrations where relevant.
Translating requirements and process designs into technical designs, then into configuration and code, making and documenting the trade-offs along the way.
Building integrations between ServiceNow and adjacent systems using appropriate patterns (REST/SOAP, IntegrationHub, Flow Designer, MID Server) and defending the choice of pattern.
Writing and maintaining automated and manual unit tests, and supporting the BA through end-to-end and multi-application testing.
Owning the technical quality of releases — code review, adherence to platform best practice, upgradeability, and keeping customisation to the minimum the requirement genuinely needs.
Taking changes through the platform governance route, including CAB submission, technical risk assessment and post-release verification.
Mentoring and technically guiding other developers, and setting the team's development standards and definition of done.
Diagnosing and resolving complex platform issues, including those arising from ServiceNow family releases and upgrades.
Working with the BA, process lead and SMEs to challenge requirements where a simpler or more sustainable technical approach exists.

Essential:

ServiceNow Certified Application Developer, plus CIS accreditation in CSM, TPSM/TSM or ITSM.
A minimum of 6years hands-on ServiceNow development experience, including complex, multi-application delivery.
Deep working knowledge of the ServiceNow platform: data model, ACLs, Flow Designer, Business Rules, Script Includes, Client Scripts, UI Builder / Service Portal, and Update Set and source control release management.
Strong JavaScript, with the judgement to know when scripting is the right answer and when configuration is.
Practical experience building with NowAssist — generative AI skills, AI agents or Virtual Agent — in a production or near-production setting, not just proof of concept.
Experience with TPSM, CSM or a comparable customer-facing ServiceNow product line, including install base and entitlement models.
Proven integration experience across REST/SOAP, IntegrationHub and MID Server, including handling authentication, error and volume concerns.
Experience through full upgrade cycles, with an understanding of what makes a build survive a family release.
Able to explain technical decisions and risk clearly to non-technical stakeholders, and to push back constructively when a requirement is unworkable.
Experience mentoring or technically leading other developers.

Desirable:

Experience with Now Assist Skill Kit, AI Search tuning, or the Generative AI Controller for third-party LLMs.
Understanding of AI governance in practice — data handling, DPIA input, model change management, output evaluation.
Experience in a software vendor, MSP or technology provider environment where the customer base sits on the platform.
Familiarity with Automated Test Framework and CI/CD tooling for ServiceNow.
Exposure to Performance Analytics or reporting design for AI agent effectiveness.

What We Do For You

Wellbeing focused – Our people are our greatest assets, and ensuring everyone feels their best self to come to work is integral.
Annual Leave – 20 days of annual leave, plus public holidays
Employee Assistance Programme – Free advice, support, and confidential counselling available 24/7.
Personal Growth - Regardless of where you are at in your career, we're committed to enabling your growth personally and professionally
Development Programmes – From Future Managers to Leadership Training, our development programmes help you get where you need to go
Online Learning Platform: SkillsHub! - Learning at your fingertips, anytime from anywhere. You can access our online library with relevant content for your career growth.
Life Insurance - 3x annual salary
Personal Accident Insurance - providing cover in the event of serious injury/illness.
Performance Bonus – Our Group-wide bonus scheme enables you to reap the rewards of your success

Who We Are

At OneAdvanced, we are at the forefront of delivering sector-focused technology solutions that simplify complexity, drive meaningful progress, and help build a fairer, more inclusive society.

We're much more than a software company. We deliver SaaS workflow applications and IT services that power organisations across Education, Government, Healthcare, Legal, Manufacturing, Housing, Retail, and more.

OneAdvanced is one of the UK's largest business software and services companies. Based in Birmingham (The Mailbox), operating across the UK, Ireland, India, and Australia.

Our secure, scalable platform, including OneAdvanced AI, our private AI service for UK organisations, powers connectivity and innovation across critical sectors. Alongside our software are our IT services, including hosting, managed services, and application modernisation.

We strive to create an inclusive workplace that drives innovation and collaboration, championing diverse perspectives and ideas. Our Environmental, Social and Governance (ESG) strategy is embedded in everything we do, guiding us to create meaningful impact for our people, our customers and the planet.

Proud to be recognised in the Financial Times Best Employers 2026 list for the second-year running , an independent and data led ranking based on employee feedback. Join us and become part of a team that's powering the world of work and making a real difference.

Join us and become part of a team that's powering the world of work and making a real difference.

Learn more at www.oneadvanced.com

ServiceNow Developer- NowAssist (12 Months FTC)