Senior Software Engineer (Java)

ARQ; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Benefits offered by this job

Stock options

Discretionary bonus

Hybrid in-office policy (3-4 days in-"

Job summary

ARQ in London seeks a Senior Backend Engineer (Java) to design, build, and scale secure backend systems powering our fintech platform.

You’ll work on greenfield projects and microservices, using Java/Spring Boot and Postgres, with a focus on maintainable code, TDD and CI/CD.

The role involves building REST APIs, evolving systems for card payments, treasury, and crypto liquidity, and collaborating with a world-class team.

Qualifications

• Demonstrable backend development experience with Java.
• Bachelor's degree in CS, math, physics or engineering.
• Strong English communication and collaboration skills.
• Experience building complex products at scale in fintech.

Responsibilities

• Design, develop, and maintain scalable backend systems.
• Build REST APIs and microservices for payments and treasury.
• Evolve systems supporting card payments, crypto liquidity and bookings.
• Embrace TDD, clean code and CI/CD practices.

Skills

Java

Backend development

TDD

DDD

Education

BS in Computer Science or related field

Tools

Spring Boot

PostgreSQL

Job description

We are building the financial system for the next century. One where control sits in the hands of customers — not banks. Where money moves on rails that are faster, smarter, and radically more efficient. Where wealth management tools help you grow your savings for decades — and build generational wealth. Where fewer intermediaries mean more value stays where it belongs: in our customers’ pockets.

We operate with long-term ambition and absolute conviction. We are not here to iterate on the past — we are here to redesign it. This is a defining moment to join us.

We are building what we believe will become one of the most important financial institutions in the world. That requires exceptional talent, relentless standards, and people who care deeply about the work. At ARQ, we are turning the financial system upside down — starting in the Americas. We are nimble, but ambitious. We move fast, learn fast, and innovate relentlessly. Technology is our greatest ally, and execution is our edge. We build as a team. We think long term. We aim for world-class in everything we do. If you are exceptional at what you do — and ready to help redefine finance — we’d love to meet you. Are you ready to build what comes next?

About the team

We believe that small teams of exceptional people outcompete massive companies with mediocre talent. That’s why we have assembled a group of people who have done it before at iconic companies like Revolut, Apple, Uber, Amazon, and Block. We’ve owned some of the most loved and profitable products in the world, delivered transaction platforms operating at massive scale, created beautiful mobile applications — and built things that have changed the lives of millions of people.

We don’t believe in 9-to-5 and we don’t believe in work-life balance as most companies sell it. We believe building the largest financial institution in the world takes long hours, every day, for years — and we like it that way. If you don’t, don’t apply.

To reshape the global financial system, we’ve raised capital from some of the world’s best investors: Sequoia Capital, Founders Fund, Brevan Howard Digital, Y Combinator, and Kaszek Ventures.

Senior Software Engineer (Java)

Location

London

Employment Type

Full time

Location Type

Hybrid

Department

About ARQ

ARQ is one of the fastest-growing fintechs in the world. Our mission is to redefine how people interact with money across borders, building the infrastructure to move value seamlessly. We’re still early in our journey, which means every person who joins shapes the future of our product, culture, and growth. If you’re excited by big challenges, global impact, and the chance to grow fast with a world-class team, ARQ is the place to do it.

What we're looking for

As a Backend Engineer, you’ll design, develop, and maintain scalable, secure, and high-performing backend systems that power our innovative products. You’ll collaborate with a talented team to create solutions that drive financial inclusion and transform the way people manage their money.

What you'll be doing

The work will focus on greenfield development and improvement of existing systems

Projects will include building REST APIs, engineering microservices and evolving a number of systems that our business depends on (e.g. card payments, treasury management, transactions booking, crypto liquidity)

Our technology stack is based predominantly on Java 25 on the backend with Postgres database

We rely on Spring Boot for quick and quality delivery

We have a pragmatic approach to develop our business logic, focusing on clean code, with emphasis on maintainability and fast turnaround with TDD, DDD and continuous integration & delivery

What you'll need

Demonstrable experience in Backend development, with fluency in Java

Bachelor's Degree (or above) in Computer Science, Mathematics, Physics, or other Engineering / Science disciplines

Quick learner with an ambitious and results driven personality, with excellent communication skills (english fluency, verbal and written)

Track record of building complex products that millions of people use in hypergrowth startups

Competitive salary and benefits

Stock options, so you own part of what you build

Discretionary performance bonus

The latest tools and technology

A world-class team that will challenge and grow your skills

The opportunity to help build the best fintech app in Latin America

Office Policy: 3-4 days a week in-office