Lead Senior Software Engineer - API Team

Design and develop robust software systems tailored to client specifications.Lead and mentor development teams to ensure project success and adherence to best practices.Translate business requirements into technical designs and solutions.Optimize applications for performance, security, and quality, ensuring high standards are met.Create and maintain comprehensive technical documentation.Provide accurate estimates for development efforts and timelines.Establish and enforce software development standards across projects.Propose innovative technical solutions to address business challenges and technical issues.Collect and analyze software metrics to drive improvements.Manage software configuration and release processes effectively.Contribute to various phases of software development including requirements analysis, testing, quality assurance, change management, and deployment.Develop testing tools and conduct thorough testing of solutions.Document development processes and create prototypes for new solutions.Provide 2nd and 3rd line support to resolve complex issues.

Who are we?Trasys International is a vibrant global organization recognized as a reliable partner to EU Institutions. With a strong dedication to excellence and a solid track record spanning over 30 years, we focus on empowering our clients' growth and success. Our mission is to facilitate clients in navigating the complexities of digital transformation by providing timely access to skilled professionals for critical roles. We continuously seek talented individuals eager to engage in challenging international projects and deliver outstanding results in multicultural settings. Our service offerings encompass modernization of solutions, digital workspaces, cloud technologies, and IT security. Headquartered in Brussels, we maintain active accounts and offices throughout Europe, including Luxembourg, Amsterdam, Athens, Stockholm, and Geneva.Is this YOU?We are currently seeking a Mid-Level SharePoint Developer to collaborate as a freelancer (preferably already registered as a freelancer in an EU member state) for a prominent EU intergovernmental agency based in Warsaw, Poland. This agency plays a vital role in assisting EU Member States with the coordination and management of external border security.The organization provides strategic direction, operational support, risk analysis, and fosters cross-border collaboration to ensure safe, lawful, and efficient mobility at Europe’s external borders.The position is classified as Near-Site, which requires you to reside within a two-hour radius of the Warsaw premises. The role allows for remote work but necessitates occasional on-site presence upon request (hence the two-hour radius).Start date: February 2026Responsibilities:Design and develop software systems.Lead development teams in execution of projects.Translate client requirements into effective design solutions.Optimize software for performance, security, and quality standards.Create and maintain technical documentation.Estimate development efforts and timelines.Establish software development standards and practices.

Location: PolandAbout Us:RTB House is a leading global technology company that specializes in cutting-edge marketing solutions for renowned brands and agencies across the globe. Our proprietary ad-buying engine, the first of its kind, utilizes Deep Learning algorithms to provide advertisers with exceptional results and to effectively meet their objectives at every stage of the marketing funnel.We invite you to join RTB House as the head of our AI Engineering Lab, a team dedicated to driving innovation through the latest advancements in Agentic AI. This position is designed for a proactive engineer and technical leader committed to architecting, developing, and deploying next-generation AI solutions that enhance engineering productivity.

At JetBrains, we are passionate about code. Since our inception in 2000, our mission has been to develop the most powerful and effective developer tools available. By automating routine checks and corrections, we accelerate production, empowering developers to innovate and create.About the InitiativeJetBrains is transitioning from standalone developer tools to a cohesive, AI-native platform for software development.AI is evolving from a mere editor assistant to an integral participant in the planning, building, reviewing, and operation of software across teams and organizations. This transformation brings forth challenges that go beyond individual tools, including governance, security, cost management, observability, and coordination between human and autonomous agents.Our aim is to establish a platform that facilitates the structured, scalable, and economically efficient adoption of AI in software development—without confining companies to closed ecosystems.We are constructing the foundation that integrates developer workflows, team collaboration, and organizational control into a cohesive system.This platform will function as the execution and governance layer for AI-driven development, seamlessly integrated with developer tools while designed for cross-team, product, and environment functionality.This initiative represents a long-term strategic investment for JetBrains and is a crucial element of our vision for the future of software development. The RoleWe are seeking a Developer Experience Lead to spearhead significant enhancements to the development experience within the JetBrains Cloud Platform (JCP).This position focuses on optimizing the productivity of JCP engineers by refining build systems, CI/CD pipelines, local development workflows, tooling infrastructure, and AI pipelines. You will be responsible for the developer experience from start to finish—covering local development, testing, CI processes, and production deployment. As this platform is rapidly evolving, many workflows and processes are still being refined. You will define what a superior development experience entails and guide the organization towards achieving it. As part of the team, your responsibilities will include:Leading and executing the strategy for developer experience enhancements across the entire JCP platform.Optimizing build systems (including Gradle, Nx, and others) for quicker builds, improved caching, and reliable scalability.Establishing AI development pipelines, managing context, agents, and transitions, and...

About Us:MARGO Group is a leading international IT consulting firm established in 2005 in Paris, with additional offices in London and Warsaw. We specialize in IT outsourcing and providing top-tier experts for intricate technology projects across Europe. Our focus is on fostering long-term partnerships, maintaining transparency, and promoting continuous development.About the Role:We are seeking a Senior .NET Developer with Angular expertise to engage in long-term enterprise banking projects within structured development environments. You will be involved in creating complex business applications while collaborating closely with Analysts, QA Engineers, and Product stakeholders.This position is intended for seasoned developers with over 5 years of experience who prioritize clean code, testing, sound architectural practices, and uphold high engineering standards.Work Model: Remote-first with scheduled on-site team meetings (2 days per month in Warsaw). Office attendance is primarily for team alignment, planning sessions, and direct collaboration.

Develop innovative ideas for refactoring existing systems.Oversee high-level architectural design and ensure it aligns with business goals.Serve as a senior developer and a guiding leader within the team.Demonstrate a proactive approach with a commitment to continuous learning and professional development.Assist business stakeholders and product owners by addressing technical inquiries and ensuring smooth delivery.Communicate complex technical concepts in a clear and understandable manner to non-technical stakeholders.Integrate innovative solutions into daily workflows.Ensure that new components and processes adhere to established architectural standards.Collaborate closely with developers in daily operations.Possess in-depth knowledge of relevant business processes and requirements.Work alongside the Java Competence Lead and other Tech Leads to enhance and streamline processes.Champion operational excellence within the team.Handle administrative responsibilities in collaboration with team members.Conduct technical interviews to assess candidate qualifications.

Join margo-group as a Fullstack Developer specializing in .NET and Angular, focusing on cloud-native applications. In this role, you will collaborate with cross-functional teams to design, develop, and deploy robust applications that leverage the power of cloud technology. If you are passionate about innovative software solutions and enjoy working in a dynamic environment, we want to hear from you!

Join the LLI Academy: Now Recruiting Junior Software Developers!We are thrilled to announce the launch of the third edition of our LLI Academy, a program aimed at identifying and nurturing talented junior developers who are passionate about technology, coding, and eager to enhance their skills in a professional setting.This initiative provides aspiring developers with the chance to gain practical experience, receive mentorship, and integrate into our vibrant team.Our previous cohorts have thrived, leading to ongoing collaboration with remarkable junior developers who have transitioned into full-time roles within our company. We are now looking for the next generation of talent to join us!About LLInformaticsLLInformatics is a progressive IT consulting firm, highly regarded by clients throughout Europe and North America. We excel in delivering complex projects with precision and quality, adhering to the highest compliance standards.Our remote-first team of over 100 experts is dedicated to creating innovative digital products that yield significant results. With an emphasis on data-driven decisions and measurable outcomes, we are setting new industry standards, supported by a strong, collaborative company culture that drives our success. Location: Warsaw (on-site for the first 3 months, then the possibility of remote work) Contract Type: UZYour Responsibilities:Develop your programming skills with guidance from mentors and a structured learning path.Implement new features and functionalities into existing projects.Address programming challenges while deepening your knowledge of Ruby.Engage in regular code reviews and receive constructive feedback from seasoned developers.Maintain and enhance existing codebases through bug fixes and refactoring.Create unit, integration, and end-to-end tests to ensure software quality.Requirements:A strong desire to learn and improve coding skills.Basic knowledge of programming languages, particularly Ruby.Ability to work collaboratively in a team environment.

Join our dynamic team based in Auckland, New Zealand, as we embark on an exciting journey to transition to a Rust codebase! We are on the lookout for passionate individuals eager to learn, grow, and contribute to our innovative projects.We encourage applications from talent around the globe who are interested in remote roles, as well as those considering relocation to Auckland. While we primarily operate in New Zealand time zones, we welcome international candidates who can maintain minimal overlap for daily stand-ups, typically held at the beginning of the New Zealand workday (9:00 AM NZT).The Role:As a Senior Software Developer in our core delivery team, you will engage in the crafting of intricate systems that extend beyond routine feature enhancements. Collaborating with a team that values software craftsmanship and autonomy, you will be instrumental in shaping our technical direction.We foster an environment that champions technical excellence, curiosity, and innovative design. We seek someone who is excited by emerging technologies and is driven to make a significant impact on how users interact with digital interfaces.Our culture is built on trust, continuous learning, and making meaningful contributions. Join a team that prioritizes integrity over ego and clarity over complexity.If you are ready to tackle real-world challenges with substantial impact and help shape the future of our solutions, we would love to hear from you!

Join our innovative team at inetum2 as a JVM Software Engineer / C Developer. In this role, you will leverage your expertise in Java Virtual Machine (JVM) and C programming to design, develop, and maintain high-quality software solutions.We are looking for someone passionate about technology, who thrives in a collaborative environment and is eager to tackle complex challenges. You will work closely with cross-functional teams to deliver robust applications that meet our clients' needs.

JetBrains is seeking an AI Lead focused on Python tools. This position centers on advancing AI technologies across the company’s product suite, with the goal of improving both user experience and product capabilities. Role overview The AI Lead will guide the development and integration of AI features into JetBrains products. The role involves direct oversight of AI project initiatives and regular collaboration with teams from various disciplines. Expect to play a key part in shaping technical direction and ensuring that Python-powered solutions continue to set a high standard in the industry. What you will do Oversee AI-focused projects from conception through implementation Work closely with engineers, designers, and product managers to align AI features with product goals Drive innovation by applying Python expertise to create and refine AI solutions Locations This role is open to candidates based in Amsterdam, Belgrade, Berlin, Limassol, London, Madrid, Munich, Paphos, Prague, remote within Germany, Warsaw, and Yerevan.

Join CD Projekt Red as a Lead Engineer in Localization, where you'll play a pivotal role in shaping the internationalization of our games. You will lead a dedicated team, ensuring that our titles resonate with audiences worldwide. Your expertise in software engineering and localization practices will drive our projects forward, enhancing player experiences across diverse languages and cultures.

Join the forefront of digital privacy with Nordsec!Are you a passionate and innovative software engineer ready to tackle complex challenges? Become a pivotal part of our dynamic team responsible for developing cutting-edge technologies such as Threat Protection Pro, the NordLynx protocol, and the world’s fastest VPN. Your contributions will empower millions of users to reclaim control over their online security, privacy, and data.

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

JetBrains is seeking an AI Lead focused on integrating artificial intelligence into the C++ ecosystem. This role shapes how AI features enhance C++ development tools, directly impacting the way engineers write and maintain code. Key responsibilities Lead initiatives that embed AI capabilities into JetBrains C++ products Collaborate with engineering teams to design and implement AI-driven solutions for software development workflows Help set the direction for AI in C++ tooling at JetBrains Locations This position is open in Amsterdam, Belgrade, Berlin, Limassol, London, Madrid, Munich, Paphos, Prague, remote (Germany), Warsaw, and Yerevan.

Join Nearmap as a Lead Senior Software Engineer on our dynamic API team, where you will spearhead the design, implementation, and delivery of innovative software solutions that align with our business goals. Your expertise will empower our developers to tackle real-world challenges faced by our users.In this pivotal role, you will collaborate closely with the Product team to analyze requirements, design robust software solutions, and elevate the capabilities of the development team through best practices and mentorship. You will have the unique opportunity to contribute to a powerful platform that manages petabytes of aerial imagery, fuels sophisticated AI models, and provides real-time geospatial insights to clients worldwide. Our systems are designed for high performance, scalability, and cutting-edge innovation, managing everything from data ingestion to API delivery and customer applications.This is a rare chance to influence quality practices across an extensive platform integrating high-resolution imagery, AI-driven insights, and scalable data delivery systems while establishing API initiatives in our new Warsaw engineering hub. Your contributions will be instrumental in ensuring the reliability of systems that are transforming decision-making processes across various industries.At Nearmap, we value versatile engineers who possess leadership skills and enthusiasm for overcoming new challenges across the full technology stack as we continue to advance our capabilities.

Join our dynamic API team as a Lead Senior Software Engineer at Nearmap, where your expertise will drive innovative software solutions that align with our business goals. You will lead a talented group of developers in designing, implementing, and delivering impactful software that addresses real-world challenges faced by our users. Collaborating closely with the Product team, you will help design software solutions that enhance our development team's capabilities by promoting best practices and mentoring individuals to reach their full potential.Your contributions will impact a sophisticated platform that processes massive volumes of aerial imagery, powers cutting-edge AI models, and provides real-time geospatial insights to clients globally. Our systems stretch the limits of performance and scalability, from data ingestion and processing to intelligent delivery through APIs and customer-facing applications.This is a unique opportunity to influence quality practices across a comprehensive platform that includes high-resolution imagery, AI-driven insights, and scalable data delivery systems, all while establishing API projects at our new engineering hub in Warsaw. You will play a pivotal role in guaranteeing the reliability of systems that are revolutionizing decision-making across various industries at scale.At Nearmap, we seek engineers who are adaptable, exhibit leadership qualities, and are eager to tackle new challenges across the full stack as we continue to advance technology.

SoftwareMind seeks a WEBCON Consultant / Team Lead in Warsaw. This position centers on digital transformation and process automation for clients aiming to streamline operations and boost collaboration. Role overview As a WEBCON Consultant / Team Lead, the work involves guiding organizations through changes that improve business processes. The focus remains on helping clients adopt automation tools and strategies that support efficiency and teamwork. Location This role is based in Warsaw.

Join the forefront of online security technology!Are you a passionate problem-solver eager to make your mark? Become a vital part of our innovative team at Nordsec, creators of Threat Protection Pro, the NordLynx protocol, and the fastest VPN available today. Our cutting-edge tools empower individuals to reclaim their online privacy, enhance security, and maintain control over their personal data.Your contribution: Play a crucial role in helping millions of users regain their online security, privacy, and data integrity.