Senior Decision Engineer

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📍 London

About this role

We’re Capital on Tap 👋
💳 Capital on Tap started because small businesses were underserved. Big banks were slow, their products weren't fit for purpose, and small business owners often couldn't access what they needed. We set out to fix that.

Today we're a financial platform - not just a credit card company. We offer a best-in-class business credit card, SME-focused spend management platform, a savings product that hit £1 billion in funds within its first year, and a growing suite of tools and financial products that make running a small business easier. 

1,000+ employees, £20bn in annual card spend, 200,000+ customers, 17,000+ Trustpilot reviews averaging 4.7 stars, and we're profitable. We’ve done a pretty good job so far, but we’re just getting started! 

The role

As a Senior Decision Engineer, you'll be a key member of our IT department's decisioning team. We own and manage the decisioning platform (GDS), where we implement customer flows, policy rules, and scorecards. You will play a crucial role in ensuring we make accurate decisions for all new applications by working closely with various teams across the company.

You should be a highly analytical and detail-oriented individual with the ability to understand and align your work with the broader business strategy. You will be expected to quickly learn new technologies and thrive in a collaborative team environment.

This position is an excellent opportunity to take on significant responsibility, lead key projects, and directly impact the success of our underwriting processes within the fast-paced financial services industry.

 

What you’ll be doing

 

  • Lead the full development lifecycle from design to implementation of our decisioning platforms.
  • Architect and maintain underwriting rules, ensuring they are robust, scalable, and aligned with business objectives, regulatory requirements, and industry best practices.
  • Design and implement advanced monitoring and alerting systems to ensure the integrity and performance of automated decisioning.
  • Collaborate proactively with Data Science, Credit, and Business Operations teams to define requirements and implement complex updates to decisioning logic.
  • Serve as a subject matter expert, working with wider IT and Engineering teams to shape data architecture and ensure the availability of reliable data for underwriting.
  • Conduct in-depth analysis to identify, troubleshoot, and resolve decisioning anomalies and underlying issues.
  • Drive the continuous optimisation of our underwriting and decisioning processes through data-driven insights and strategic initiatives.

 

We're Looking For

  • 4+ years of experience working with decision engines, within the financial services or FinTech industry (examples include GDS Link, Experian Powercurve and Provenir).
  • Strong proficiency in data manipulation and a solid working knowledge of Python is essential. You should also have experience with SQL and a desire to learn other relevant languages like LUA.
  • Proven ability to independently solve complex problems and deliver effective, end-to-end solutions.
  • A proactive and curious mindset with a track record of identifying opportunities for improvement.
  • Excellent communication and stakeholder management skills, with the ability to present complex technical information clearly to both technical and non-technical audiences.

Diversity & Inclusion 🌈
We welcome, consider and encourage applications from anyone who shares our commitment to inclusivity. Join us in creating a space where authenticity thrives, and everyone can do their best work.

Great Work Deserves Great Perks
We try not to take ourselves too seriously (all the time) so we make sure our office is decked out with a pool table, arcade machine, beer tap, and a couple of office dogs thrown in for good measure. Check out our benefits:
🏥 Private Healthcare including dental and opticians services through Vitality
✈️ Worldwide travel insurance through Vitality
🎁 Anniversary Rewards (£250, £500, £750, 4-week fully paid sabbatical)
👛 Salary Sacrifice Pension Scheme up to 7% match
🚘 Octopus EV Salary Sacrifice Scheme

🏖️ 28 days holiday (plus bank holidays)
📖 Annual Learning and Wellbeing Budget
👪 Enhanced Parental Leave
🚲 Cycle to Work Scheme
🚂 Season Ticket Loan
💬 6 free therapy sessions per year
🐶 Dog Friendly Offices
🍫 Free drinks and snacks in our offices

Check out more of our benefits, values and mission here.

Other Info
👍Check out our ‘Top Tips’ for interviewing.
✔️Keep updated on new job opportunities by following us on Linkedin.
📧Email careers@capitalontap.com if you have any questions.

Excited to work here? Apply!
If you’d like to progress your career within our fast growing, profitable fintech then click apply and we will aim to get back to you within 3 working days (during busy periods this could take up to 5 working days.)

Frequently Asked Questions

Is the salary disclosed for the Senior Decision Engineer position at capitalontap?
The salary for this Senior Decision Engineer role at capitalontap is not publicly listed. Click "Apply Now" to learn more about the compensation package on their official careers page.
Where is the Senior Decision Engineer position at capitalontap located?
This Senior Decision Engineer role at capitalontap is based in London. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Which team or department does the Senior Decision Engineer at capitalontap belong to?
This Senior Decision Engineer position is part of the IT department at capitalontap. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Senior Decision Engineer position at capitalontap?
Click the "Apply Now" button on this page. You will be redirected to capitalontap's official application portal hosted on greenhouse where you can submit your application directly.
When was the Senior Decision Engineer job at capitalontap posted?
This Senior Decision Engineer position at capitalontap was posted on May 27, 2026. Apply as soon as possible — early applications are often reviewed first.
Senior Decision Engineer
capitalontap
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