Mobile and Backend Software Engineer - Banking

Be an Early ApplicantFull TimeHybrid

LondonPosted Today

Role Overview

Capitalontap is hiring a Mobile and Backend Software Engineer - Banking. This is a full-time hybrid role, based in London. Part of Capitalontap's Backend hiring, posted today. applications are still in the early window, before most candidates have applied. Full responsibilities, required qualifications, and the apply link are listed in the description below.

Salary Context

Salary is not disclosed in this posting. Market median for Backend roles is $135k-$165k (based on 14 comparable listings). Many employers share specifics during the interview process or after an initial screen.

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SwiftKotlinSQLRailsGCPAzureMongoDBFirebase

Job description

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, the team work from our London Offices 2 days per week.

The Team

The Banking and Repayments teams sit at the heart of Capital on Tap's product, owning the core account experience for thousands of small business customers. Banking manages account operations, transaction lifecycles, balance management, ClearBank integration, and savings. Repayments owns the repayment rails, including the most recent open banking repayments.

We value engineers who take genuine ownership, work autonomously, and bring depth across the stack. This is a high-priority hire with real impact from day one.

What You'll Be Doing

As a Senior mobile and backend Software Engineer, you'll own the back-end systems that power our Banking and Repayments platform , while also contributing to mobile - helping transition mobile and front-end ownership from our Customer Experience team into Banking.

Design and build robust, scalable back-end services in C#/.NET
Own the full SDLC - from feature inception through to production, monitoring, and continuous improvement
Contribute to mobile development across iOS and Android using Flutter, Kotlin, and/or Swift
Collaborate with Product, Design, and QA from early feature shaping through to delivery
Write thorough unit and integration tests and uphold high engineering standards
Identify bottlenecks and drive improvements across the team
Work cross-functionally, bridging technical decisions with business goals

What We're Looking For

Mobile development experience in Flutter/Dart, Kotlin, or Swift - this is a firm requirement

Strong back-end engineering experience, ideally in C#/.NET
Solid testing practice across unit and integration testing
Experience with CI/CD platforms such as CodeMagic or similar
Comfortable working in Agile environments
Autonomous and collaborative - you take ownership and see things through

Our Tech Stack

Backend: C#, .NET, .NET Core
Mobile: Flutter, Dart, Riverpod, GoRouter, Kotlin, Swift
Databases: SQL Server, MongoDB, Firestore
Cloud: GCP (Firebase) and Azure
CI/CD: CodeMagic

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.)

About Capitalontap

Capitalontap

BackendHybrid

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Frequently Asked Questions

How do I apply for the Mobile and Backend Software Engineer - Banking position at Capitalontap?

Use the Apply button above to submit your application directly to Capitalontap. Most applications take less than 5 minutes if your resume and contact details are ready, and you'll be routed to the employer's official application system to finish.

Is the Mobile and Backend Software Engineer - Banking role at Capitalontap remote or in-office?

This is a hybrid role based in London. Expect a mix of in-office and remote days, with the specific cadence set by the hiring manager.

What does a Mobile and Backend Software Engineer - Banking at Capitalontap earn?

Capitalontap has not disclosed a salary range in this posting. Many employers share specifics later in the interview process; you can also ask during a recruiter screen if compensation transparency is important to you.

When was the Mobile and Backend Software Engineer - Banking role at Capitalontap posted?

This role was posted on July 9, 2026 (today). It's still listed as actively hiring; we re-confirm openings against the source system multiple times per day and remove closed roles.

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