Senior Software Engineer
Confirmed on the employer's own hiring board on Oct 1, 2026. First seen by Alion on May 19, 2026. Capital on Tap scores A on the Alion truth index.
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!
This is a hybrid role, our engineering teams work from our London (Moorgate) Office 2 days per week.
The Role
We're looking for Senior Software Engineers to help us build the products that small businesses across the UK and US rely on every day. You'll work across cross-functional teams alongside Product Managers, QA Engineers, and fellow Software Engineers, owning problems end to end, from the first line of code through to production, monitoring, and continuous improvement.
This isn't a role for someone who wants to be handed a ticket and told what to build. We're looking for engineers who understand the problem, challenge the approach when it needs it, and take pride in the quality of what they ship. We only build what the customer wants.
What You’ll Be Doing
- Designing and building robust, scalable solutions in .Net/C#, taking full ownership of the SDLC from concept through to production
- Playing an active role in architectural decisions and technical direction, shaping how things are built, not just building them
- Working closely with Product and QA, bringing your technical perspective early and often
- Writing bulletproof unit and integration tests and holding a high bar for code quality across the team
- Communicating clearly across technical and non-technical stakeholders, translating complex engineering decisions into business context
- Mentoring and supporting engineers around you, raising the standard of the team as well as your own output
We’re Looking For
Required skills:
- 5+ years of hands-on experience in C#, .Net and SQL Server; React and Typescript are a strong plus
- A clear sense of what senior means. Not just years in the seat, but ownership, judgement, and the ability to operate with ambiguity
- Strong testing practices across unit and integration testing
- Broad engineering knowledge that goes beyond your core stack; the kind of depth and curiosity that comes from solving hard problems in complex, distributed systems
- The ability to communicate clearly and confidently, with your team, with Product, and with the wider business
- Experience working in agile, cross-functional teams
- Someone who's proactive, direct, and makes the people around them better
Our Tech Stack
- Backend: C#, .Net, .Net Core
- Frontend: React, Typescript
- Mobile: Flutter, Dart
- Databases: SQL Server, MongoDB
- Cloud: Azure & GCP
Interview Process
- First stage: 30-minute intro, CV review, and values with a Talent Partner
- Second stage: 45-minute “Tech Chat” with a Team Manager
- Final stage: 90-minute Code Pairing + 30-minute Values Interview
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
Other Info
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Email [email protected] 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.)