---
title: 'iOS Engineer at Referrals Only'
canonical: 'https://feeny.ai/job/ios-engineer-referrals-only-cardiff-london-or-p64f7j94x268'
type: 'job'
last_seen: '2026-09-07'
---

# iOS Engineer at Referrals Only

- **Company:** Referrals Only
- **Location:** Cardiff London OR, United Kingdom
- **Work type:** remote
- **Posted:** 2025-10-06
- **Last confirmed live:** 2026-09-07
- **Apply:** https://job-boards.greenhouse.io/monzoreferrals/jobs/7300321

## Job description

📍London/ UK remote | 💰 [Engineer III](https://monzo.com/documents/engineering-progression-framework-v4-1.pdf) £78,000 - £110,000 base salary per year ➕ share options | [Benefits](https://monzo.com/careers/) | [Technology](https://monzo.com/blog/technology)

## About our Mobile Engineering discipline

Our mobile engineers have a variety of different backgrounds

There are ~60 iOS engineers at Monzo and we’re looking for more to join the team. We have several non-graduates; only some of us studied Computer Science; some of us have worked in huge companies; some have only ever worked in startups; others are former consultants. As long as you enjoy learning new things, we’d love to talk to you.

Monzo works in small, interdisciplinary teams

We have around 650 engineers out of roughly 5,500 people in total - and we have big ambitions. There are many interesting challenges ahead, and we're happy for people to move between teams or to specialise, whatever you prefer. As an engineer here you'd be able to work directly with anyone across the company, and we run regular knowledge-sharing sessions so you’ll learn heaps about everything from how banks work to effective communication.

We contribute to [open source software](https://github.com/monzo) as much as possible. Our [blog](https://monzo.com/blog/technology) is a good place to learn even more about what we do!

## Your day-to-day

We’re searching for product-focused iOS engineers to evolve our native mobile app. You’ll take pride in building polished user experiences, and you’ll balance the need for well-tested resilient code with moving fast and iterating.

You’ll be working on a product that is a part of day to day life for more than 15 million people already, and your work here will shape the way that people interact with their finances.

As an iOS Engineer at Monzo you'll work in a small, autonomous product squad alongside Android Engineers, Backend Engineers, User Researchers, Product Designers, Product Managers, QA Testers, and Data Scientists.

You and your team will be responsible for an overall company goal, rather than building a specific feature - you'll have the opportunity to have impact on both what we build, and how we build it. Mobile engineers at Monzo work on everything from the personal banking product to customer support tools. We also have a small mobile platform squad dedicated to enabling other engineers to move faster.

Every week we meet as an iOS discipline to discuss tools, techniques, problems we're encountering across the company and work together to improve our codebase and processes.

You'll report to an engineering manager who will meet with you every 1-2 weeks 1:1. They’re dedicated to helping you grow and develop as an engineer.

Our iOS app

Our app is 100% [Swift](https://www.swift.org/) and our latest features are built in [SwiftUI](https://developer.apple.com/tutorials/swiftui/) and using elements of [The Composable Architecture](https://github.com/pointfreeco/swift-composable-architecture). Historically we built using a Model, View, View-Model architecture (MVVM). We use Coordinators to ensure we can re-use flows wherever possible, and avoid tightly coupling one screen to another. We make heavy use of protocols and extensions throughout our app.

Our networking stack is built upon [Alamofire](https://github.com/Alamofire/Alamofire), using a generic interface to easily de-serialise objects of a certain type, and we mirror our backend micro-service architecture by building individual services to house our API logic. We log liberally to get alerted when they’re triggered in [Sentry](https://sentry.io/welcome/) which we also use to monitor crashes.

Our testing stack comprises of unit tests for business logic, stubbed API tests for pseudo-integration tests, snapshot tests for UI, and XCUITest for testing user input and sequencing.

We've published some talks and blog posts about how we work:

- [Working with backend services on iOS](https://monzo.com/blog/2017/07/07/working-with-backend-services-on-ios/)
- [Pushing Protocols to their Limits](https://www.youtube.com/watch?v=jDvk7nztqHw)
- [Our mobile release process: An illustrated story](https://monzo.com/blog/2022/06/23/our-mobile-release-process-an-illustrated-story)
- [What we’ve learnt building a design system in SwiftUI](https://www.leedsmobile.com/past-talks#h.pxrhbkspk22g)

You should apply if

- You care about the impact your work has on our customers, and optimise for outcomes rather than the number of lines of code you output
- You’re excited about and have experience in programming in Swift
- You’ve shipped and iterated on at least one app in the App Store
- You have a product mindset: you care about customer outcomes and you want to make data-informed decisions
- You love turning excellent design into beautiful products
- You’re comfortable working in a team that deals with ambiguity
- You have an understanding computer science principles

The Interview Process

Our interview process involves three main stages:

- Initial Call
- Take home task or pair coding exercise
- Final interview including a system design and a behavioural interview

Our average process takes around 2-3 weeks but we will always work around your availability.

You will have the chance to speak to our recruitment team at various points during your process but if you do have any specific questions or want to talk through reasonable adjustments ahead of or during application please us at any point on tech-hiring@monzo.com

Please also use that email to let us know if there's anything we can do to make your application process easier for you, because of disability, neurodiversity or any other personal reason.

There’s a detailed blog on [the interview process](https://monzo.com/blog/2022/03/22/preparing-for-mobile-interviews-at-monzo), for extra details, hints and tips.

How we work 💻:

Locations & Flexible Working :

Our main tech hub is in London, but our engineers live everywhere in the UK— from Brighton to the Western Isles.

We value meeting in person but there’s no pressure to come into the office, even if you're nearby. We believe you'll do your best work if you are where you want to be. If you live outside of London and we ask you to come into the office, Monzo will support you with the costs. ✨

Our offices are naturally social, especially Tuesdays, Wednesdays and Thursdays, which happen to line up with our twice-weekly Monzo lunches & treat Thursdays 🍽️. Teams also schedule time together often for work and play – in or around the office, or online.

Set up a work schedule that delivers impact and fits your life.

At Monzo, we value connections, flexibility, and wellbeing. We keep our meetings during core hours to stay connected and believe in maintaining work/life balance.

You’ll be empowered to manage your work in a way that suits you and your team, giving you the freedom for children drop-offs and pick-ups, walking your dog or adventurous cat, avoiding peak commuting times or gym slots, appointments, or supporting your family in an emergency. 🕒✨

Work the way that works for you with Monzo! 💼

## What's in it for you

💰 £78,000 - £110,000 base salary per year ➕ plus stock options +[Benefits](https://monzo.com/careers/), we also provide all of our engineers with the latest MacBook Pro.

✈️ We can help you relocate to the UK

✅ We can sponsor visas but please note we aren't able to support remote working outside of the UK at the moment

📍 This role can be based in our London office, but we're open to distributed working within the UK (with ad hoc meetings in London)

⏰ We offer flexible working hours and trust you to work enough hours to do your job well, at times that suit you and your team

📚 Learning budget of £1,000 a year for books, training courses and conferences

➕ And much more, see our full list of benefits[here](https://monzo.com/careers/)

## #LI-ZM1 #LI-REMOTE

## About Referrals Only

## Company Overview
- **One-liner**: Marqeta is the world’s first modern card issuing platform, providing open APIs that enable businesses to create, manage, and scale customized payment card programs.
- **Entity Type**: Public (Ticker: MQ on NASDAQ)
- **Headquarters**: Oakland, California, USA
- **Founded**: 2010
- **Founders**: Jason Gardner (Founder & Executive Chairman)

## Core Business
- **Primary industry**: Financial Technology (Fintech) — Modern Card Issuing & Payment Solutions
- **Target customers**: B2B; serves a wide range of industries including digital banking, on-demand delivery, buy now, pay later, expense management, retail, and workforce payments. Customers include Square, DoorDash, and other high-growth fintech and enterprise companies.
- **Mission or purpose statement**: To simplify payments and enable any company to deliver delightful payment experiences natively, powering more flexible, engaging, and innovative payment products.

## Products & Services
- **Modern Card Issuing Platform (SaaS/API)**: Fully open API platform that allows developers to launch new credit and debit card programs with speed, flexibility, and scale. Supports instant wage access, embedded finance, and custom card products.
- **Compliance & Risk Management (Service)**: Integrated fraud detection, spend control, and compliance tools to ensure high levels of security and uptime.
- **Global Expansion Capabilities (Platform)**: Certified to operate in over 40 countries across the US, Europe, and Asia, enabling businesses to scale globally.

## Market Standing
- **Valuation/Market Cap**: As a public company, market cap fluctuates. As of mid-2026, Marqeta is a publicly traded company valued in the multi-billion dollar range (exact figure varies with market conditions).
- **Key Metric**: Annual Revenue — $383 billion+ in total volume processed in 2025; 80x volume growth since 2017; 99.99% platform uptime in 2025.
- **Notable Investors/Partners**: Key customers include Square (Block), DoorDash, and other leading fintech and enterprise firms. Partners include issuing banks, networks (e.g., Visa, Mastercard), and card fulfillment providers.
- **Growth Signals**: Recognized as a CNBC Disruptor (top 50 in 2021 award); consistent expansion into new geographies (EU, UK, Asia); continued hiring across multiple departments and regions (US, Canada, UK).

## Competitive Advantages
- **First-mover & category leader**: Marqeta defined the modern card issuing category with its open API platform, giving it a decade-plus head start over competitors.
- **Scalability & reliability**: Proven track record of 99.99% uptime and handling massive transaction volumes (80x growth since 2017) — critical for enterprise customers.
- **Deep integration with major networks**: Pre-existing relationships with Visa, Mastercard, and issuing banks shorten time-to-market for customers.
- **Developer-first approach**: Open APIs and developer tools make it easy for engineering teams to build custom payment experiences quickly.

## Strategic Focus
- **Global expansion**: Continuing to expand its certified operations into new countries (currently 40+) to serve multinational customers.
- **Embedded finance & new use cases**: Driving adoption in instant wage access, embedded finance, and enterprise expense management.
- **AI & automation**: Investing in AI-powered fraud detection, risk management, and product automation (e.g., hiring for Principal Security Engineer, Product & AI; Lead Product Manager, Enterprise AI & Automation).
- **Platform stability & security**: Maintaining industry-leading uptime and security compliance as core differentiators.

## Why Work Here
- **Culture & values**: Marqeta emphasizes a culture of “Simplify and Innovate,” “Solve for the Customer,” “Do What’s Right,” “Make it Count,” and “Win as a Team.” Employee Resource Groups (ERGs) include BlackCard, HOLA, RepresentAsian, Desi, MQ-Proud, Vets@MQ, Women’s Group, Parents’ Group, and Marqetaglots.
- **Remote/hybrid policy**: Many roles are remote (US, Canada, UK), with some positions based in Oakland, CA or London, UK. The company supports flexible work arrangements.
- **Notable perks & engineering culture**: Fast-paced, purpose-driven environment; strong focus on developer experience and open APIs; opportunities to work on cutting-edge payment infrastructure at massive scale. The company invests heavily in early career talent and internal mobility.
- **Award-winning workplace**: Recognized as a top workplace (e.g., CNBC Disruptor) and offers a collaborative, inclusive environment.

## Sources
1. [Marqeta About Us](https://www.marqeta.com/company/about-us)
2. [Marqeta Careers Page](https://www.marqeta.com/company/careers)
3. [Marqeta Homepage](https://www.marqeta.com/)
4. [Greenhouse Job Board](http://job-boards.greenhouse.io/marqeta)
5. [MQ Referrals Job Board](https://job-boards.greenhouse.io/mqreferrals/jobs/7743043)

## Other roles at Referrals Only

- [Product Manager, Subscriptions](https://feeny.ai/job/product-manager-subscriptions-referrals-only-barcelona-0jkx6zdsjnj7) — Barcelona, Spain
- [Fraud Investigator, Overnight Team](https://feeny.ai/job/fraud-investigator-overnight-team-referrals-only-united-kingdom-weayv59k72r1) — United Kingdom
- [Lead Market Researcher](https://feeny.ai/job/lead-market-researcher-referrals-only-cardiff-london-or-83qyn2ncq2qk) — Cardiff London OR, United Kingdom
- [Chief of Staff, Group CFO](https://feeny.ai/job/chief-of-staff-group-cfo-referrals-only-london-fg8xem42f7fh) — London, United Kingdom
- [Senior Product Manager - Growth](https://feeny.ai/job/senior-product-manager-growth-referrals-only-london-x8w3pax4qj7r) — London, United Kingdom
- [Director of Product Design](https://feeny.ai/job/director-of-product-design-referrals-only-cardiff-london-or-8ca0hy3vyc09) — Cardiff London OR, United Kingdom
- [Staff Backend Engineer](https://feeny.ai/job/staff-backend-engineer-referrals-only-cardiff-london-or-6w1n8z0gktm9) — Cardiff London OR, United Kingdom
- [Senior Backend Engineer](https://feeny.ai/job/senior-backend-engineer-referrals-only-cardiff-london-or-0weyav3xnjw9) — Cardiff London OR, United Kingdom
- [Backend Engineer III](https://feeny.ai/job/backend-engineer-iii-referrals-only-cardiff-london-or-awnc2afx215n) — Cardiff London OR, United Kingdom
- [Android Engineer](https://feeny.ai/job/android-engineer-referrals-only-cardiff-london-or-zgy3wbdg3pyh) — Cardiff London OR, United Kingdom