Senior Java Software Engineer

StoneX Group Inc.; Kraków; Hybrid; PLN 180,000 - 260,000; Full time

Job summary

StoneX Group Inc. is hiring a Senior Java Software Engineer in Kraków for the EIT Dev Technology Internal Hub. You will contribute across the full development lifecycle, design and architect solutions, mentor teammates, and deliver robust, scalable code in an Agile environment.

The role requires strong Java expertise, REST/microservices experience, and a proactive, collaborative attitude. Hybrid work arrangement and a 12-month B2B contract are offered.

Qualifications

• Advanced English speaking/writing.
• 5+ years of Java experience in a professional environment.
• 5+ years of relational database experience (SQL).
• 5+ years of REST APIs, micro-services, databases, unit testing, version control (Git) and Agile methodology.
• Great knowledge/experience in messaging platforms (Kafka, RedPanda).
• Can do attitude to work.
• Take accountability for technical designs and justify solutions.
• Professionalism in handling constructive feedback and learn/adapt.
• Strong work ethic and attention to detail.

Responsibilities

• Contribute to all phases of the development lifecycle within Agile methodology.
• Take responsibility for the design and architecture of technical solutions.
• Mentor other technical members in the team.
• Write well designed, testable and efficient code.
• Ensure designs follow specifications and review procedures.
• Collaborate with other developers, BAs, and QAs.
• Document all components/methodologies as required.

Skills

Advanced English communication

5+ years Java experience

5+ years relational databases

5+ years REST APIs & microservices

Agile methodology

Strong problem solving

Effective interpersonal skills

Education

University degree in Computer Science or Software Engineering

Tools

Spring Boot

Kafka/Redpanda

PostgreSQL

MSSQL

Git

CI/CD DevOps

Azure

gRPC

Unit/Integration Testing

Job description

Overview

Permanent, full-time, B2B

Connecting clients to markets – and talent to opportunity.

With 5,400+ employees and over 80,000 institutional, commercial, and payments clients, we operate from more than 80 offices spread across six continents. As a Fortune 100, Nasdaq-listed provider, we connect clients to the global markets – focusing on innovation, human connection, and providing world-class products and services to all types of investors. Whether you want to forge a career connecting our retail clients to potential trading opportunities, or ingrain yourself in the world of institutional investing, StoneX Group is made up of four business segments that offer endless potential for progression and growth

Business Segment Overview:

Come join the Nexus project, an ambitious initiative to consolidate all StoneX customer-facing systems into a single application. You’ll be working on a squad within a 150+ global team. Our squad is responsible for delivering multiple features of the user interface for use by tens of thousands of customers.

Technology Ecosystem

• Back End: Java 21+, Spring Boot, REST APIs, Kafka/Redpanda, gRPC, PostgreSQL, MSSQL, Unit/Integration Testing
• Architecture: Micro-services, event-based architecture
• Cloud: CI/CD DevOps, Azure, GitHub Enterprise

Responsibilities

Position Purpose: Senior Java Software Engineer working within EIT Dev Technology Internal Hub department.

• Contribute to all phases of the development lifecycle working within Agile methodology
• Take responsibility for the design and architecture of technical solutions
• Mentor other technical members in the team
• Write well designed, testable and efficient code
• Ensure designs follow specifications and follow review procedures
• Collaborate with other developers, BAs, and QAs
• Document all components/methodologies as required

Qualifications

To land this role you will need :

• Advanced English speaking/writing
• 5+ years of Java experience in a professional environment
• 5+ years of relational database experience (SQL)
• 5+ of REST APIs, micro-services, databases, unit testing, version control (Git) and Agile methodology Great knowledge/experience in messaging platforms (Kafka, RedPanda)
• "Can do” attitude to work
• Take accountability for technical designs and justify solutions to wider technical/non-technical members
• Professionalism in handling constructive feedback and learn/adapt
• Sound verbal/written communication abilities
• Effective interpersonal skills
• Sense of urgency
• Honesty, curiosity, and tenacity
• Strong work ethic and emphasis on attention to detail

What makes you stand out:

• Great knowledge/experience in DevOps and CI/CD

Education / Certification Requirements

• University qualification in Computer Science, Software Engineering or similar discipline or great GitHub portfolio showcasing your most recent projects.

Working environment

• Hybrid 4-days in office (we have private parking for employees)
• B2B contract for 12 months