Backend Engineer (Java) — Build Greenfield Fintech APIs

ARQ; Polska; On-site; PLN 180,000 - 300,000; Full time

Benefits offered by this job

Competitive salary

Own development process

Latest technology

Strong team

Job summary

ARQ is seeking a Backend Engineer to design, develop, and maintain scalable Java-based backend systems powering our fintech products. You will build REST APIs, microservices, and work on systems like payments and treasury management. Strong emphasis on TDD, DDD, and CI/CD.

You should have a Bachelor's degree in CS/Math/Physics or engineering, fluent English, and a track record of delivering complex products used by millions in hypergrowth startups. Competitive salary and modern tech.

Qualifications

• Demonstrable Backend development experience with Java.
• Bachelor's degree in CS/Math/Physics or engineering/science.
• Fluent English in speaking and writing.
• Proven track record building complex products used by millions in hypergrowth startups.

Responsibilities

• Focus on greenfield development and improving existing systems.
• Build REST APIs and microservices; evolve systems critical to business (payments, treasury, transactions, crypto liquidity).
• Backend stack on Java 25 with Postgres; use Spring Boot for rapid delivery.
• Embrace clean code, TDD, DDD, CI/CD and maintainability.

Skills

Java

English fluency

Strong communication

Experience with high-traffic apps

Education

Bachelor's degree in CS/Math/Physics/Engineering/Science

Job description

ARQ is seeking a Backend Engineer to design, develop, and maintain scalable Java-based backend systems powering our fintech products. You will build REST APIs, microservices, and work on systems like payments and treasury management. Strong emphasis on TDD, DDD, and CI/CD.

You should have a Bachelor's degree in CS/Math/Physics or engineering, fluent English, and a track record of delivering complex products used by millions in hypergrowth startups. Competitive salary and modern tech.