Backend Software Engineer - Golang or Java - Lisbon/Berlin Based

About Us

1GLOBAL is a technology-driven global mobile communications provider helping enterprises and consumer brands deliver seamless connectivity worldwide. Powered by a best-in-class telecom platform, proprietary eSIM technology, and its own mobile core network across 15 countries, 1GLOBAL operates as a fully regulated telecommunications provider in 43 countries.

Founded in 2022, 1GLOBAL has rapidly become one of Europe's fastest-growing telecom technology companies, connecting more than 80 million people and devices globally. Our customers include leading banks, multinational enterprises, global retailers, travel companies, payment service providers, and digital-first businesses.

Headquartered in the Netherlands, with R&D hubs in Lisbon, Berlin, and São Paulo, 1GLOBAL employs over 550 professionals across 16 countries. With annual revenues exceeding US$200 million and a strong track record of profitability, we continue to invest in innovation, infrastructure, and international expansion as we redefine the future of global mobile connectivity.

About the Team

You will be joining a dynamic team at the forefront of developing and maintaining our Network API, xSIM Management System, and Recording Platforms. The Network API powers critical systems and services that enable the creation, configuration, and real-time monitoring of subscriber configurations across a wide array of business scenarios. These include enterprise solutions, IoT deployments, regulatory compliance, and recording services, ensuring seamless connectivity for everyone and everything. Our xSIM Management System is a high-performance, low-latency platform designed to handle hundreds of transactions per second, keeping all xSIMs accurately updated in real time. Meanwhile, our Recording Platforms deliver robust Mobile Compliance & Recording capabilities tailored for financial institutions, automatically capturing client and employee interactions either on-premises or through our secure cloud infrastructure.

We run a multi-site platform, following strict security requirements, provide the service to customers around the world and manage millions of subscriber profiles. We embrace a highly collaborative and diverse environment, value teamwork, autonomy and hold ourselves accountable for our deliverables and customer success.

About the Role

Provide accurate effort estimates to support roadmap planning and effective expectation management

Design and implement resilient, scalable, secure, and fault-tolerant architectures to ensure system reliability and performance

Develop new features and support existing systems across the Network API, xSIM Management System, and Recording Platforms

Contribute with small, incremental enhancements that seamlessly integrate into the established codebases

Maintain and update existing solutions to keep them modern, efficient, and reliable

Collaborate with team members to ensure smooth development processes and shared understanding

Write and maintain comprehensive tests to ensure fast regression and reliable validation of new features

Implement procedures and metrics to enable effective monitoring and observability of platform contributions

Participate in code reviews to promote high standards of code quality, readability, and maintainability

Take ownership of the quality and outcomes of your work, ensuring fully functional end-to-end flows

Create and maintain accurate, up-to-date technical documentation

Actively contribute to team discussions, with a mindset for continuous improvement and openness to new ideas or technologies

About You

Must-haves

6+ years of professional experience in backend development, preferably with Go (Golang). Strong Java experience with willing to learn Go is also welcome

Strong understanding of concurrency models, with practical experience in implementing asynchronous workflows, inter-process communication, and synchronisation techniques

Skilled in designing, building, and consuming RESTful APIs, following best practices for API design and performance optimisation

Proven experience working with databases, both relational (e.g., PostgreSQL) and non-relational (e.g., Redis, MongoDB, DynamoDB), including data modelling, query optimisation, and performance tuning

Experienced in writing unit tests, integration tests, and benchmarks, with a test-driven development mindset

Comfortable with networking protocols and distributed communication patterns (e.g., gRPC, WebSockets, TCP/UDP)

Experienced in building scalable microservices architectures and distributed systems

Knowledgeable in applying software engineering best practices and design patterns for maintainable, testable code.

Skilled in using DevOps tools and practices, including Docker, CI/CD pipelines, and Infrastructure as Code

Familiar with Git workflows and collaborative development processes such as pull requests, code reviews, and agile methodologies

Demonstrated accountability for technical outcomes and ownership of end-to-end feature delivery

Effective communicator in English, both written and verbal, suitable for a remote and largely asynchronous work environment

Nice-to-haves

Proficient in writing idiomatic Go code, with solid understanding of the language’s core features such as interfaces, structs, composition, and error handling

Competent in profiling and performance tuning using Go’s built-in tools such as pprof and trace, with a focus on optimisation

Demonstrated experience with event-driven architectures, including the implementation of producers and consumers using platforms like Kafka, RabbitMQ, or ActiveMQ

Solid hands-on experience deploying, monitoring, and maintaining applications on Kubernetes

Working knowledge of cloud platforms (e.g., AWS, GCP, Azure, Oracle Cloud) with experience deploying cloud-native applications

Hands-on experience with observability and monitoring tools like Prometheus and Grafana

Experience with MSML and SIP is a strong plus

Why 1GLOBAL?

Growth Opportunities: Advance your career in one of the fastest growing telecommunications companies, expanding over 50% 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.