Mid/Senior Java Developer at altersolutions | Warsaw

About Us1GLOBAL is an innovative technology leader in mobile communications, offering unparalleled global connectivity solutions for both enterprises and consumers. Our cutting-edge telecom platform features a robust, owned global mobile core network, state-of-the-art in-house developed eSIM technology, and a wide array of telecom licenses, allowing us to operate as a fully regulated telecommunications provider in 40 countries around the globe.We proudly serve some of the world’s most prominent banks, enterprises, and digital-first businesses, including neo-banks, global FMCG leaders, travel industry giants, and payment service providers. Currently, we empower over 70 million people and devices worldwide, facilitating our clients to launch, scale, and innovate confidently within the mobile ecosystem.1GLOBAL is a rapidly growing, profitable entity, projecting full-year revenues exceeding US$200 million and profits over US$25 million by 2025. Our robust cash flow supports continuous investments in infrastructure, platform innovation, and global expansion. Recent years have been pivotal for us, marked by significant enterprise and consumer client acquisitions that enhance our status as a formidable global mobile connectivity provider, dedicated to helping consumer brands thrive in telecommunications.Founded in 2022 by seasoned technology entrepreneurs Hakan Koç and Pyrros Koussios, 1GLOBAL is at the forefront of 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 premier R&D centers in Lisbon, Berlin, and São Paulo, our team of nearly 500 experts across 15 countries is unified by a singular mission: to redefine global mobile connectivity through unparalleled technology, scale, and operational excellence.About the TeamThis senior, hands-on Java position focuses on scalable backend systems, long-term ownership, and addressing real-world production challenges. You will be part of a newly formed backend team in Warsaw, dedicated to advancing our eSIM, global connectivity platform, and IoT solutions.The role entails:Enhancing and modernizing existing systems,Developing new services and greenfield components,Boosting reliability, performance, and maintainability across the platform.As a senior engineer, you will also lead the evolution of testing methodologies as systems evolve.

Join us at capital, a premier trading platform expanding globally. Our award-winning products, recognized for their advanced technology and exceptional client experience, set the standard in the industry. We are on the lookout for top-tier talent to join our dynamic engineering team.We are currently enhancing our Backend Team and seeking passionate Java Software Engineers with a keen interest in trading! Our engineering team is crucial in maintaining the performance, security, and reliability of our products. With a focus on delivering superior performance, ensuring compliance, and protecting client data, your contributions will significantly enhance the trading experience for our clients.We value engineers who not only write exceptional code but also embody our core values. We are searching for individuals who are ready to move quickly, willing to innovate and develop, who understand the importance of listening, respecting, and supporting, strive to exceed client expectations, and take full ownership for achieving real impact.

About the Role Nearmap is looking for a Software Engineering Manager to guide the Web Platform team in Warsaw. This role involves leading engineers focused on building and improving web solutions that support user experience and business objectives. What You Will Do Direct a team of engineers working on the web platform Work with cross-functional groups to clarify project needs and set schedules Oversee delivery of software projects, keeping quality and deadlines in focus Encourage a culture centered on technical growth and ongoing improvement Location This position is based in Warsaw.

Join our dynamic Product Security team as a Senior Platform Security Engineer, where your expertise will be crucial in safeguarding our platform that supports multiple products and handles sensitive, high-value information. With our operations expanding, we seek two professionals to strengthen our security efforts.Your role will involve hands-on engineering, where you will design, build, and deploy robust security and privacy controls. This is not about merely defining policies; you will actively contribute to the security architecture of our systems.Your responsibilities will include enhancing supply-chain security through SAST, SCA, container scanning, and CI/CD hardening. Expect a varied role that will challenge you across multiple domains without confining you to a single specialty.What Success Looks Like:Within 90 days, you will have implemented significant, production-level security enhancements.You will take ownership of components of the AuthN/AuthZ model and its execution.You will develop a comprehensive understanding of our data flows and associated privacy risks.Establish yourself as a trusted advisor across teams, able to confidently voice concerns and provide rationale.Effectively reduce risk through practical measures rather than superficial security actions.Your Work Style:This role offers a high degree of autonomy, encouraging you to identify and address issues independently.You will collaborate closely with engineers from different teams, fostering a culture of teamwork.Engaging in constructive disagreements is encouraged, with decisions rooted in data and threat modeling.You will have the authority to block releases on security or privacy grounds when necessary, following clear escalation paths.Proactively addressing problems, even beyond your immediate area, is expected.

Join Our Team as a Software Engineer!We are seeking a talented Software Engineer to become a key member of Bolt’s Data Platform Insights team. In this role, you will be responsible for developing and enhancing the platform that empowers Bolt teams to create and manage high-quality data products. Your contributions will ensure that data is both reliable and accessible, driving impactful decisions at a massive scale.About BoltWith more than 200 million customers across over 50 countries, Bolt stands as one of the fastest-growing tech companies in Europe and Africa. Our success is attributed to our dedicated team members, and we are committed to fostering an inclusive environment where every individual is welcomed, irrespective of race, color, religion, gender identity, sexual orientation, age, or disability.Our vision is to transform cities into spaces designed for people rather than vehicles. We need your expertise to help us achieve this mission!About the RoleAs a Software Engineer in the Insights team, you will play an essential role in shaping the data ecosystem at Bolt. You will deliver frameworks, libraries, and automations that facilitate the seamless building, testing, and deployment of thousands of data models, metrics, and BI reports. Collaborating closely with data producers, you will tackle their toughest challenges and develop scalable, elegant platform solutions. We are committed to solving complex engineering problems at scale, ensuring that Bolt’s data modeling ecosystem remains reliable, cost-effective, and high-performing.

Altersolutions is seeking a Senior Platform Engineer (Developer Experience) to lead the establishment and standardization of engineering practices, enhance developer workflows, and define standards for CI/CD and collaboration. This role melds hands-on DevOps expertise with a strong focus on clarity, comprehensive documentation, and effective process design.The primary objective is to boost the efficiency, consistency, and scalability of our engineering organization. In this capacity, you will collaborate closely with engineering leads, product managers, and other key stakeholders to ensure our operational methods are thoroughly documented, clear, and actionable.Key ResponsibilitiesDesign, document, and maintain comprehensive software development processes, encompassing coding standards, branching strategies, testing protocols, release management, and deployment workflows.Engage with engineering managers, team leads, and product teams to gather insights and best practices, facilitating the seamless adoption of tools and methodologies.Convert intricate technical workflows into clear, concise documentation and visual aids (such as flowcharts, process maps, checklists, and templates) to enhance understanding.Assess and implement tools aimed at improving developer experiences (e.g., feature flagging, local development environments, code quality tools).Oversee a central documentation repository (e.g., Confluence, Notion, or Git-based systems), ensuring that all documentation remains current and version-controlled.

We are seeking a highly skilled Senior Microsoft Platform/System Engineer to join our dynamic team at Altersolutions in Warsaw. In this role, you will leverage your deep expertise in Microsoft technologies to deliver innovative solutions that drive business success. Your contributions will be instrumental in enhancing our clients' systems and infrastructure.As a key member of our engineering team, you will collaborate with cross-functional teams to design, implement, and optimize Microsoft-based solutions. Your experience will help guide best practices and ensure the highest quality of service delivery.

We are seeking a highly skilled Senior Java Developer to join our talented team at altersolutions. In this role, you will be instrumental in designing, developing, and deploying robust Java applications that meet our clients' needs. Your expertise will help drive innovation and efficiency within our projects.The ideal candidate will possess a deep understanding of Java technologies, frameworks, and best practices. You will collaborate with cross-functional teams to deliver high-quality software solutions on time and within budget.

Oversee the technical management of SimCorp Dimension along with associated enterprise applications.Diagnose and resolve incidents within stipulated operational timelines.Conduct routine software updates and maintenance tasks.Ensure technical documentation is maintained and regularly updated.

Join Turnitin as a Senior Fullstack/Backend Software Engineer, where your expertise in backend development, particularly with Java and serverless architectures, will be pivotal. We are seeking engineers who are enthusiastic about creating scalable distributed systems and delivering robust software solutions for our acclaimed educational platform.As an integral member of our shared services team, you'll spearhead the development and enhancement of the core systems supporting both our existing and upcoming applications.Key Responsibilities:Architect, develop, and optimize scalable backend services utilizing Java and serverless technologies (AWS Lambda).Design and implement RESTful APIs and event-driven architectures.Contribute to frontend component development as required.Enhance performance and cost-effectiveness of existing services.Collaborate with cross-functional teams, including Architects, Product Managers, and engineering leads, to deliver innovative solutions.Mentor junior developers and promote best practices.Establish and manage CI/CD pipelines.Maintain high-quality coding standards through peer reviews, automated testing, and compliance with development best practices.Document shared components comprehensively, providing usage guidelines and examples.

Location: Poland About Us: RTB House is a leading global company that specializes in providing cutting-edge marketing technologies for renowned brands and agencies worldwide. Our unique ad-buying engine stands out as the world's first fully Deep Learning-powered platform, enabling advertisers to achieve exceptional results and meet their objectives throughout every stage of the marketing funnel. We are currently seeking talented engineers to join our Platform Engineering team within the Bidding Platform structure. If you have a passion for system-related topics such as deployment, monitoring, databases, and load balancing, along with experience in leading complex project specifications and coordinating team efforts, we want to hear from you! This is an excellent opportunity for those eager to tackle technically challenging and sophisticated solutions.

Docplanner has spent over ten years reimagining how people experience healthcare. The company began by questioning whether patients truly sat at the center of care, and has since helped millions share reviews about their medical visits. Alongside this, Docplanner has introduced digital tools that make appointment management easier for doctors. The goal remains clear: make healthcare more human and accessible. Today, Docplanner operates in 13 countries and supports over 90 million patients each month. More than 300,000 healthcare professionals use the platform. Backing from investors like Point Nine Capital, Goldman Sachs Asset Management, and One Peak Partners has fueled steady growth. The team now includes over 2,500 employees, yet still values the entrepreneurial spirit that shaped its early years. Tech at Docplanner The Docplanner Tech team brings together more than 400 engineers, data scientists, and product experts. Many have built long careers here, contributing to a culture that values both innovation and lasting collaboration. New team members are welcomed with genuine enthusiasm. For more insights into the company’s culture, see Glassdoor reviews or watch this video. What makes work here meaningful? Projects at Docplanner have a direct impact on healthcare for millions. The company values individuality and encourages people to bring their full selves to work. Diverse perspectives are seen as essential to better solutions. The workplace supports both remote and virtual collaboration, making it easy to contribute from anywhere. Location details The Senior Platform Engineer - AI Innovations role is based in Warsaw. Remote-friendly options are available.

Join our dynamic ML Platform team at Bolt as a Senior ML Platform Engineer, where you will play a pivotal role in designing, developing, and optimizing our AI Infrastructure. This infrastructure powers Bolt's intelligent services, making machine learning and artificial intelligence easier to implement at scale.We are a rapidly growing tech company with over 200 million customers across more than 50 countries. Our mission is to create cities that prioritize people over cars, and we believe an inclusive environment is key to achieving this goal. We welcome applicants from all backgrounds and walks of life.

At Endava, we pride ourselves on being at the forefront of technology innovation. As a Senior Java Developer, you will play a pivotal role in designing, developing, and releasing sophisticated software solutions using various programming languages, frameworks, and libraries. Collaborating within cross-functional teams, you will adapt to challenges and focus on delivering exceptional client outcomes.This position is full-time (UoP) and requires in-office work at one of our locations in Kraków, Warsaw, or Gdańsk twice a week.Key Responsibilities:Architect, estimate, and implement technical solutions for applications of medium to high complexity.Engage actively throughout the entire application development lifecycle.Work closely with stakeholders to clarify requirements, processes, architecture, and priorities.Advocate for industry standards, tools, and practices (such as DevOps) to ensure high-quality software delivery.Identify opportunities for improvement and escalate risks/issues linked to development activities.Review and provide feedback on the work of fellow developers.Continuously learn and apply new technologies and methodologies relevant to ongoing projects.Participate in tech communities, conferences, and events.Share insights and experiences gained from various projects.

Role overview Sigma Software Group is hiring a Senior Data Engineer in Warsaw to focus on integrations and the data platform. This position involves designing and building solutions that connect data across the company’s platforms. Collaboration with teams throughout the organization is central to keeping data moving reliably and strengthening the overall data architecture. What you will do Design and implement data integration solutions for various platforms Work closely with cross-functional teams to keep data flowing seamlessly Optimize and maintain data pipelines for performance and reliability Monitor data quality and drive improvements where needed Apply best practices in data management Support the ongoing development of the company’s data architecture Impact This role plays a key part in enabling data-driven decision making at Sigma Software Group. By ensuring reliable, high-quality data is available when needed, the Senior Data Engineer helps establish data as a strategic asset for the organization.

Location: Poland (Remote/Flexible) About Us: RTB House is a pioneering global technology company that specializes in cutting-edge marketing solutions for leading brands and agencies around the world. Our innovative ad-buying engine is the first globally to leverage Deep Learning algorithms exclusively, empowering advertisers to achieve remarkable outcomes and fulfill their objectives at every level of the marketing funnel. We are in search of Senior Engineers to join our Bidding Platform team, which forms the backbone of our RTB operations, processing over 20 million requests per second to engage in real-time auctions and deliver advertisements to audiences across more than 90 countries. If you are eager to tackle technically intricate challenges and develop robust solutions, this role is tailored for you! Your Responsibilities: Architect and spearhead the implementation of system modifications to enhance performance, scalability, and observability for global ad display and tracking. Create tools and optimizations that yield measurable advancements in critical user performance metrics. Develop, test, deploy, monitor, and maintain HTTP/gRPC services and batch jobs in Java and Python, ensuring compliance with high engineering standards across all aspects, including setup, configuration coding, and production monitoring. Offer technical leadership: tackle complex system challenges, engage in project planning and scoping, and uphold the highest coding standards through active participation in code reviews.

Role Overview Miratech is looking for a Senior Full Stack Developer with experience in Java and Angular. Based in Warsaw, this role joins an engineering team that delivers solutions for a range of client projects. What You Will Do Work on full stack development tasks using Java and Angular Collaborate with engineers to build and improve client-facing applications Contribute to project planning and technical discussions What We Offer Opportunities to develop technical skills in a team setting Collaborative work environment Projects that support client success

Join our dynamic team at evooq as a Senior Software Engineer! In this role, you will leverage your extensive experience in software development to design, implement, and maintain high-quality software solutions that meet our client’s needs. You will collaborate closely with cross-functional teams, contributing to all stages of the development lifecycle. If you are passionate about technology and eager to make a significant impact, we want to hear from you!

Role overview SmartRecruiters is seeking a Senior Software Engineer with strong Python skills to join the team in Poland. This role focuses on building and enhancing scalable software that supports the company’s product suite. Senior engineers at SmartRecruiters play a key part in shaping technical decisions and work closely with colleagues from various teams. What you will do Design and implement software solutions using Python Work with product managers, designers, and engineers to deliver new features Promote development best practices and contribute to architectural choices Mentor junior engineers and help them grow technically Requirements Experience building scalable applications with Python Comfort working in a collaborative setting that can move quickly Interest in solving practical problems with technology Ability to share knowledge and support less experienced team members