Software Engineer (Java Backend)

KASZEK; Greater London; Hybrid; GBP 60,000 - 90,000; Full time

Benefits offered by this job

Competitive salary and benefits

Stock options

Discretionary performance bonus

Latest tools and technology

World-class team

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

Job summary

KASZEK is looking for a Backend Engineer to design and maintain scalable backend systems that support financial inclusion. You will work in a hybrid model, collaborating with a talented team and building systems that enhance how people manage money.

The role demands experience in Java and backend development, with opportunities to contribute to innovative fintech solutions. The position offers competitive salary, stock options, and the chance to work in a dynamic startup environment.

Qualifications

• Demonstrable experience in backend development.
• Fluency in Java required.
• Track record of building complex products in hypergrowth startups.

Responsibilities

• Design, develop, and maintain scalable backend systems.
• Build REST APIs and engineer microservices.
• Focus on clean code and maintainability with TDD, DDD.

Skills

Backend development experience

Fluency in Java

English communication skills

Experience in startups

Education

Bachelor's Degree in Computer Science or related field

Tools

Java

Postgres

Spring Boot

Job description

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.

Location

London

Employment Type

Full time

Location Type

Hybrid

Department

Engineering

Job Description

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.

Responsibilities

• 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

Qualifications

• 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

Benefits

• 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