About Us
1GLOBAL is a technology-driven global mobile communications provider, delivering global connectivity solutions to enterprises and consumers. Powered by a best-in-class telecom platform - including its own owned and operated global mobile core network, fully fledged in-house developed eSIM technology, and an extensive portfolio of telecom licenses - 1GLOBAL operates as a fully regulated telecommunications provider across 40 countries worldwide.

We serve many of the world's leading banks, enterprises, and digital-first businesses, including neo-banks, global fast moving consumer goods companies, travel leaders, and payment service providers. Today, 1GLOBAL connects more than 70 million people and devices globally, enabling our customers to launch, scale, and innovate with confidence in the mobile ecosystem.

1GLOBAL is a profitable, fast-growing business. With full-year revenues in 2025 exceeding US$200 million and profits of over US$25 million, we generate strong cash flows to fund our growth allowing us to continuously invest in infrastructure, platform innovation, and global expansion. Recent years have marked a defining phase in our journey, with major enterprise and mass-consumer client wins accelerating our evolution into a global mobile connectivity powerhouse, purpose-built to enable consumer brands to enter and succeed with their own  aspirations to offer telecommunications services to their clients.

Founded in 2022 by experienced technology entrepreneurs, Hakan Koç and Pyrros Koussios, 1GLOBAL has rapidly emerged as a European technology leader shaping the future of global telecommunications. We operate as a fully regulated Mobile Virtual Network Operator (MVNO) in 12 countries and as a regulated telecom operator in an additional 28 markets. Headquartered in the Netherlands, with world-class R&D hubs in Lisbon, Berlin, and São Paulo, our team of close to 500 experts across 15 countries is united by a single ambition: to redefine global mobile connectivity through technology, scale, and execution excellence.
About the Team

This is a senior, hands-on Java role focused on scalable backend systems, long-term ownership, and real production challenges.

You'll join a new backend team in Warsaw working on the evolution of our eSIM, global connectivity platform, and IoT solutions.

The role combines:

• scaling and modernizing existing systems,
• building new services and greenfield components,
• and improving reliability, performance, and maintainability across the platform

As a senior engineer, you'll also contribute to introducing and evolving testing approaches as systems grow and change.

Our technology stack: Java 17 / 21, Spring / Spring Boot, Hibernate / JPA, Kafka, RabbitMQ, Redis, PostgreSQL, MySQL, AWS, Docker, Kubernetes, Git, Maven, CI/CD pipelines

Fluency in English is essential for this role, please ensure your CV is submitted in English as part of your application.

About the Role

• Design, build, and maintain Java backend services
• Contribute to architecture decisions with focus on scalability, resiliency, and security
• Work on existing services, legacy modernization, and greenfield initiatives
• Build and integrate REST APIs
• Work with messaging systems and data stores
• Advocate for clean code, testing, and maintainable solutions
• Participate in code reviews and technical discussions
• Collaborate closely with your Team Lead and peers
• Work in an Agile, collaborative environment, contributing to planning and continuous improvement
• Mentor other engineers when needed
  
  
  

About You 

• 5+ years of professional experience in Java backend development
• Experience working with production backend systems
• Solid understanding of REST APIs, databases, and messaging
• Experience with unit, integration, and e2e testing
• Familiarity with CI/CD pipelines and modern development workflows
• Experience working with Git, Docker, and Kubernetes-based environments
• Good understanding of cloud services and scalable infrastructure
• Ability to work independently and take ownership
• Fluent English (spoken and written)
  
  
  

Why 1GLOBAL?

• Growth Opportunities: Advance your career in one of the fastest growing telecommunications companies, expanding over 100% year-on-year under the leadership of successful tech entrepreneurs
• Major Transaction Exposure: Be in the driver's seat for transactions that will have an impact on the future telco industry
• Work with a Talented Team: From the Board and the Founders to the Senior Management Team, you will collaborate daily with the most capable and renowned external advisors, and constantly being exposed to talented and driven individuals
• Dynamic Work Environment: Thrive in a collaborative, fast-paced workplace where innovation is encouraged, and every contribution counts
• Professional Development: Work alongside industry experts to enhance your skills and knowledge in a cutting-edge field
• International Experience: Gain opportunities to work in different 1GLOBAL offices around the world as you grow within the company
• Open Communication Culture: Join a team where your ideas are heard, and open dialogue is encouraged, fostering a supportive and transparent work environment
• Get Things Done Attitude: Be part of a results-driven team that values efficiency, creativity, and the drive to make a tangible impact in the industry

1GLOBAL is an equal opportunity employer, we value your character as much as your talent. Diversity drives our innovation, and we offer a collaborative, dynamic, and international work environment. We are excited for you to join our mission to revolutionise connectivity globally.