Senior Java Backend Engineer - Fintech, Scalable

Mangopay; Warszawa; On-site; PLN 240,000 - 360,000; Full time

Job summary

Mangopay, a wallet-based payment infrastructure, is seeking a Senior Software Engineer to join an agile team in a distributed, highly available platform. You will write code, set standards, and raise the engineering bar across the organization.

You will work on architecture, drive design decisions, and collaborate with product managers to deliver scalable fintech capabilities with robust monitoring and continuous deployment.

Qualifications

• You have 7+ years as a Backend developer using Java (Java 11 through Java 21+).
• You have experience building high-throughput, low-latency products in fintech/payments.
• You have experience with cloud native frameworks in large-scale production systems.
• You work in modern cloud architecture using AWS or similar clouds.
• You have deep experience designing scalable, event-driven systems using Kafka or RabbitMQ.
• You can write unit tests and functional tests with JUnit 5 or Spock.

Responsibilities

• Participate in day-to-day development with architectural decisions and code reviews.
• Ensure adherence to architectural principles while defining new standards.
• Collaborate with engineers, architects, and product managers to break down problems.
• Maintain system monitoring, alerting, and proactive failure detection.
• Partner with Engineering Manager to drive technical and organizational improvements.

Skills

Java backend

Low-latency fintech

Micronaut / Spring

Cloud AWS

Kafka / RabbitMQ

JUnit 5 / Spock

AI-assisted tools

Event-driven architecture

Code review & QA

Team mentoring

Tools

Micronaut

Spring Cloud

Kafka

RabbitMQ

Job description

Mangopay, a wallet-based payment infrastructure, is seeking a Senior Software Engineer to join an agile team in a distributed, highly available platform. You will write code, set standards, and raise the engineering bar across the organization.

You will work on architecture, drive design decisions, and collaborate with product managers to deliver scalable fintech capabilities with robust monitoring and continuous deployment.