Senior Java Software Engineer

1GLOBAL is a technology-driven global mobile communications leader, built to help enterprises unlock the full potential of mobile connectivity at scale. Powered by a best-in-class telecom platform – including our own owned and operated global mobile core network, a full end-to-end eSIM technology stack, and an extensive portfolio of telecom licenses – 1GLOBAL operates as a fully regulated telecommunications provider across 40 countries worldwide. Combined with our privileged access to the global wholesale telecom market, this positions us uniquely to deliver seamless, compliant, and scalable connectivity solutions anywhere in the world.

We serve many of the world's leading banks, enterprises, and digital-first businesses, including neo-banks, 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 exceeding US$200 million and profits of over US$25 million, we generate strong cash flows and fund our growth independently—continuously investing 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  telecommunications offerings.

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.

Position Overview

We are looking for a talented engineer to join our Consumer Group. You will join a development team responsible for the product delivery and in-life management of our B2C (betterroaming) and B2B2C (API powering Revolut, nordVPN, etc.) products. The talented team is eager to learn and experiment with new technologies. We value teamwork and embrace a culture of fully owning our deliverables, meaning we are both autonomous and accountable for them.

We are open to hiring candidates for this role in Warsaw, Poland, and Lisbon, Portugal.

Key Responsibilities

• Build high-impact features and contribute to the architecture design; aim towards resiliency, scalability, security and fault tolerance;
• Advocate for high code quality, readability and high tests coverage;
• Promote best practices for a high-scale web (or mobile) environment;
• Work with an Agile methodology;
• Identify areas of improvement in the codebase and promote them through seamless integrations, documenting solutions and new flows;
• Mentor junior members when needed and contribute with meaningful reviews.

Requirements

• 3-5+ years of experience in Java software development;
• Experience with unit/integration/e2e testing (test-driven development is a plus);
• Proficiency with REST APIs, both in implementing and consuming the interfaces;
• Experience with development tools and processes (Git-flow, peer reviewing);
• Familiarity with relational databases, CI/CD flows, Git, Docker, and Kubernetes;
• Good understanding of cloud services and scalable infrastructure;
• Excellent communication skills (fluent in English, both written and spoken), with a self-motivated and autonomous mindset.

Benefits

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.