Lead Software Architect (Java) at KAYAK | Berlin

KAYAK, part of Booking Holdings (NASDAQ: BKNG), runs a large-scale travel search platform used by travelers worldwide to find flights, hotels, rental cars, and vacation packages. The company also offers KAYAK for Business, which provides travel management solutions to organizations. Its network includes well-known brands like momondo, Cheapflights, and HotelsCombined. KAYAK aims to make exploring the world easier by building the best travel search engine and values innovation and real impact from its employees. Role overview As a Senior Java Software Engineer based in the Berlin office, you will play a key role in developing and refining the features behind KAYAK’s search and booking systems. The team collaborates with over 200 travel partners, giving users access to more than 500,000 hotels and 550 airlines. Your work will help ensure smooth, reliable experiences for millions of users each day. This position requires onsite presence in Berlin at least three days per week. What you will do Enhance search and booking algorithms to meet the needs of major corporate clients worldwide. Develop and maintain high-performance integrations with third-party APIs, including those for airlines, hotels, and rental car providers. Take ownership of your designs from concept through deployment, with a focus on code quality and system performance. Join code reviews and architectural discussions to keep the K4B project modular and reusable as KAYAK continues to grow. Requirements Bachelor’s degree in Computer Science or a related field. At least 4 years of professional experience working with Java. Strong knowledge of the Spring ecosystem (Spring/Spring Boot) and hands-on experience with both relational (SQL) and NoSQL databases such as PostgreSQL, MySQL, or Redis. Clear and effective communication skills in English. Ability to independently design and deliver engineering projects.

KAYAK, a proud member of Booking Holdings (NASDAQ: BKNG), stands as the premier travel search engine globally. With an immense volume of queries across our diverse platforms, we assist travelers in discovering their ideal flights, accommodations, rental vehicles, and vacation packages. Our innovative corporate travel solution, KAYAK for Business, is revolutionizing the business travel landscape.As part of KAYAK, you will join a travel enterprise that encompasses a range of renowned metasearch brands, including momondo, Cheapflights, and HotelsCombined. From our humble beginnings to our current status as an industry leader, we thrive on innovation, encouraging every team member to leave their mark. Our mission centers on creating the most effective travel search engine, simplifying global exploration for everyone.In the role of Security Engineer at KAYAK, you will leverage cutting-edge technologies to execute top-tier security protocols. We value innovative thought as a key driver in safeguarding both our corporate and customer data. We are eager to welcome inventive and driven individuals who are passionate about engineering to propel these efforts forward! More details about our security program can be found at KAYAK Security.This position requires working from our Berlin, Germany office three days a week.Key Responsibilities:Enhance security measures in our endpoint, on-premises, and cloud IT environments.Monitor and investigate potential security threats.Conduct routine scanning and auditing of critical systems.Contribute to the development of security incident response protocols.Assist in managing and deploying state-of-the-art security tools.

KAYAK is part of Booking Holdings (NASDAQ: BKNG) and operates as a leading travel search engine. The company processes billions of queries across its platforms, helping travelers find flights, hotels, rental cars, and vacation packages. KAYAK also develops solutions for business travel, including KAYAK for Business. The Berlin office is home to a growing team that works on a portfolio of well-known metasearch brands such as momondo, Cheapflights, and HotelsCombined. Innovation remains central to KAYAK’s approach, and each team member has the opportunity to contribute to the company’s mission: building the best travel search engine for effortless global exploration. This Full Stack Engineer role focuses on developing and improving KAYAK’s B2B platform. The platform serves established clients and is positioned for further growth. The position is based in Berlin and requires in-office presence at least three days per week. What you will do Work closely with a global team to develop B2B products. Partner with designers, product managers, and commercial teams to define and deliver new features. Design and build scalable, high-performance solutions. Contribute to architecture decisions that improve performance, quality, and code reusability. Troubleshoot and resolve recurring technical issues. Use AI coding tools to increase productivity. Requirements Degree in Computer Science or a related field. At least 5 years of professional experience in web development. Strong skills with TypeScript, React, and CSS (Sass or Less) for front end work. Experience with Java, Java Spring, JVM ecosystems, and familiarity with databases such as PostgreSQL, MySQL, or Redis. Comfort with writing unit and end-to-end tests. Proven debugging ability in a full-stack environment. Benefits Health Insurance 401k

About KAYAKKAYAK, a member of Booking Holdings (NASDAQ: BKNG), stands as a premier travel search engine. With billions of queries on our platforms, we assist travelers in discovering their ideal flights, accommodations, rental cars, and vacation packages. We are also revolutionizing business travel with our innovative corporate travel solution, KAYAK for Business.As part of KAYAK, you will join a travel company that oversees a diverse array of global metasearch brands, including momondo, Cheapflights, and HotelsCombined. From our startup journey to becoming an industry trailblazer, innovation drives us, and every team member has the chance to leave a lasting impact. Our commitment is to develop the most efficient travel search engine, simplifying the process for everyone to explore the world.Position OverviewWe are in search of a proficient mid-level Java backend developer dedicated to implementing new features and maintaining KAYAK’s cutting-edge search and booking technology. Collaborating with over 200 travel partners and connecting to more than 500,000 hotels and 550 airlines, you will play a pivotal role in a dynamic team that ensures seamless operations, aiding millions in finding optimal accommodations and travel routes every day!This is a Fixed Term contract until September 30, 2027.This role requires working from our Berlin office a minimum of three days per week.Key ResponsibilitiesEnhance search and booking algorithms to meet the needs of our largest global corporate clients.Develop and sustain high-performance integrations with third-party APIs (airlines, hotels, and rental car providers).Take full ownership of your designs, from concept to deployment, while upholding exceptional standards for code quality and performance.Engage in code reviews and architectural direction to ensure the K4B project remains modular and reusable as KAYAK expands its enterprise reach.QualificationsBachelor’s degree or higher in Computer Science or a related field.5+ years of experience in Java programming.Hands-on experience with the Spring ecosystem (Spring/Spring Boot) and familiarity with relational (SQL) and NoSQL databases (e.g., PostgreSQL, MySQL, Redis).Excellent English communication skills.Ability to design and implement engineering initiatives with a focus on performance and usability.

Join Our Innovative Team at 1GLOBALAt 1GLOBAL, we are redefining mobile connectivity on a global scale. As a leading technology-driven mobile communications provider, we deliver seamless connectivity solutions for both enterprises and consumers. Our advanced telecom platform, featuring our proprietary global mobile core network and in-house developed eSIM technology, empowers us to operate as a fully regulated telecommunications provider across 40 countries worldwide.We partner with some of the world’s premier banks, enterprises, and digital-first businesses, including neo-banks and global consumer goods companies. With over 70 million connections, we enable our clients to innovate and scale their operations confidently within the mobile ecosystem.As a profitable and rapidly growing business, we project revenues exceeding US$200 million in 2025, with profits surpassing US$25 million. Our strong cash flow allows us to invest continuously in our infrastructure, platform innovations, and global expansion initiatives. Our recent successes have marked a pivotal phase in our journey, with significant client acquisitions propelling us into a global mobile connectivity powerhouse.Founded in 2022 by seasoned tech entrepreneurs Hakan Koç and Pyrros Koussios, 1GLOBAL is quickly emerging as a European technology leader, committed to shaping the future of global telecommunications. As a fully regulated Mobile Virtual Network Operator (MVNO) in 12 countries and a regulated telecom operator in another 28, we are headquartered in the Netherlands with R&D hubs in Lisbon, Berlin, and São Paulo. Our dedicated team of nearly 500 experts across 15 countries is driven by a singular ambition: to enhance global mobile connectivity through innovative technology and operational excellence.About the RoleDesign and develop impactful features while contributing to the architectural framework with a focus on resilience, scalability, security, and fault tolerance.Champion high code quality and best practices to maintain robust software development.Work collaboratively in an agile team environment to ensure timely product delivery and management.

Join Atolls, the world's largest community-driven shopping platform, active in over 20 markets.We empower millions to make informed spending choices across the discovery, evaluation, and (re-)purchase phases by connecting consumers with the right brands and retailers.Our diverse team of over 1,000 individuals across 10 countries develops products that millions use daily at a global scale. Here, you'll have true ownership of your work and witness its direct impact. Are you ready to help shape the shopping experiences that people trust? Keep reading.About This Opportunity:We are on the lookout for a Senior Software Engineer (Java/SpringBoot) to enhance our Shopping team based in Berlin. In this pivotal role at Atolls, you will play a critical part in enabling our consumers to maximize their value for money by delivering an outstanding shopping rewards experience online and in-store. You'll be instrumental in crafting exceptional user experiences, empowering consumers to make informed and confident shopping decisions. Your contributions will directly influence how millions of users engage with our platforms, guiding them towards making smart, fair, and rewarding choices.Our Perks:At Atolls, we are committed to fostering your professional and personal development. Here’s what we offer:A culture that champions personal and professional growth, coupled with internal mobility opportunities.A supportive and inclusive team that values diverse perspectives and innovative ideas.32 days of paid vacation plus your birthday off for optimal work-life balance.A flexible hybrid working model to accommodate your lifestyle.Access to a dedicated learning budget and internal training.Mental health coaching to support your well-being.Regular global and local events to celebrate achievements and foster connections.Opportunity for a sabbatical after three years with the company.

Join our innovative team at SWARCO as a Senior Java Developer in Berlin. In this pivotal role, you will be responsible for designing, developing, and maintaining high-quality software solutions that drive our projects forward. Your expertise in Java programming will be crucial in crafting robust applications that meet the needs of our clients.

airapps seeks a Software Architect to define and guide the architecture of software solutions aligned with business objectives. This position is based in the Berlin Metropolitan Area. Key responsibilities Design and architect scalable applications that can grow with business needs Collaborate with cross-functional teams throughout the development lifecycle to ensure product reliability Provide leadership in software design and implementation, setting standards and direction for development teams Location This role is located in the Berlin Metropolitan Area.

Role overview airapps seeks a Mobile Software Architect based in the Berlin Metropolitan Area. This role shapes how new mobile solutions are designed and built, working closely with cross-functional teams. The main goal is to create applications that enhance user experience. What you will do Design and develop mobile applications from initial concept to final delivery Collaborate with product, design, and engineering teams to ensure smooth integration Address technical challenges to deliver reliable and scalable mobile solutions What airapps values Strong interest in mobile technology Enjoyment in solving complex problems and finding practical answers Commitment to delivering high-quality user experiences

KAYAK, a subsidiary of Booking Holdings (NASDAQ: BKNG), stands as a premier travel search engine. With billions of queries processed across our platforms, we empower individuals to discover their ideal flight, accommodation, rental vehicle, and travel package. We are also innovating the business travel sector with KAYAK for Business, our corporate travel solution.As a member of KAYAK, you will engage with a travel entity that encompasses a suite of global metasearch brands, including momondo, Cheapflights, and HotelsCombined. From our inception as a start-up to our current position as an industry leader, innovation remains at the heart of our operations, providing every employee with the chance to leave their mark. Our mission is to develop the finest travel search engine, simplifying the experience of exploring the world for everyone.KAYAK is in search of a Senior Digital Designer to join our Marketing team, spearheading the visual development of our campaign assets, landing pages, and modular design systems. In this pivotal role, you will significantly influence how our global audience engages with our diverse brands, including Swoodoo, checkfelix, momondo, and Cheapflights. You will harmonize high-level creative ideation with a systematic design approach, ensuring each interaction point—from brand activations to partner-facing media solutions—is visually striking and functionally sound.In this position, you will design and construct custom landing pages utilizing our modular system while also influencing its future evolution. Collaborating across various teams—Global Brand Design, Growth Marketing, and Media Solutions—you will create components that are adaptable, inclusive, and aligned with our brand identity. This role necessitates a designer who embodies 'systems thinking', adept at independently steering design concepts with prompt execution while possessing a profound grasp of digital best practices and cultural trends.Please note that this role requires commuting to our Berlin office at least three times a week.

About Us1GLOBAL is a pioneering global mobile communications provider, dedicated to delivering innovative connectivity solutions for both enterprises and consumers. With a cutting-edge telecom platform that includes our proprietary global mobile core network, advanced in-house developed eSIM technology, and a comprehensive array of telecom licenses, 1GLOBAL operates as a fully regulated telecommunications provider across 40 countries.We proudly serve leading banks, enterprises, and digital-first businesses, including neo-banks, fast-moving consumer goods firms, travel industry leaders, and payment service providers. Currently, 1GLOBAL connects over 70 million individuals and devices worldwide, empowering our clients to confidently launch, scale, and innovate within the mobile ecosystem.1GLOBAL is a profitable and rapidly expanding enterprise, with projected full-year revenues surpassing US$200 million and profits exceeding US$25 million in 2025. Our strong cash flow allows us to continually invest in infrastructure, platform innovation, and global expansion. Recent years have marked a transformative phase in our journey, with significant enterprise and mass-consumer client acquisitions propelling our evolution into a dominant force in global mobile connectivity, specifically designed to support consumer brands in their telecommunications ventures.Founded in 2022 by seasoned tech entrepreneurs Hakan Koç and Pyrros Koussios, 1GLOBAL has swiftly established itself as a European technology leader reshaping the future of global telecommunications. As a regulated Mobile Virtual Network Operator (MVNO) in 12 countries and a telecom operator in an additional 28 markets, we are headquartered in the Netherlands with exceptional R&D centers located in Lisbon, Berlin, and São Paulo. Our team of nearly 500 experts across 15 countries is united by a singular goal: to redefine global mobile connectivity through technology, scale, and execution excellence.About the TeamWe are seeking a skilled and experienced engineering leader to join our newly formed team. You will collaborate with an international group, spearheading the development of 1GLOBAL's eSIM platform, which encompasses both consumer and IoT solutions. We value teamwork and foster a culture of total ownership over our deliverables, ensuring that we are both autonomous and accountable. Our primary focus is on our customers and our commitment to building and delivering valuable propositions.Fluency in English is essential for this role; please ensure your CV is submitted in English as part of your application.

Join our innovative team at redcare-pharmacy as a Senior Java Engineer. In this pivotal role, you will leverage your expertise in Java programming to develop robust, scalable applications that enhance our digital pharmacy solutions. Collaborate with cross-functional teams to drive the design and implementation of high-quality software solutions.We are looking for a proactive and detail-oriented engineer who thrives in a dynamic environment and is passionate about problem-solving. If you are ready to make a significant impact in the healthcare technology space, we want to hear from you!

Join enpal as a Tech Lead and take the helm of our innovative team in Berlin. We are seeking a tech-savvy leader to guide our engineering efforts, drive technological advancements, and ensure the delivery of cutting-edge solutions. You will collaborate with cross-functional teams, mentor junior developers, and play a pivotal role in shaping the future of our tech landscape.

Doctolib is hiring a Software Engineer with solid experience in Java and Kotlin. This position is based in Berlin and centers on building digital products that support both patients and healthcare professionals across Europe. Role overview This role involves working on software that aims to improve healthcare access and efficiency. The team values collaboration and a shared commitment to making a difference in the medical field. What you will do Collaborate with team members to design and implement new product features Develop and maintain applications using Java and Kotlin Help create solutions that make healthcare services easier to access and manage Location This role is based in Berlin, Germany.

Join our innovative team at Lightspeed Commerce Inc. as a Senior Software Developer specializing in Java. In this pivotal role, you will work on our Third Party Ecosystem, contributing to the development of cutting-edge software solutions that enhance our platform's connectivity and flexibility.As a Senior Software Developer, your expertise will guide our projects, ensuring high-quality code and efficient workflows. Collaborate with a talented team of developers and stakeholders to drive our technology forward, fostering an environment of continuous improvement and excellence.

Join our Clickout-to-Revenue Team, where you'll be integral to our core business model: merchants pay for qualified redirects ("Clickouts") to their shops. Your role will ensure that this monetization operates smoothly, efficiently, and transparently, significantly contributing to idealos' growth.Your ResponsibilitiesEnd-to-End Responsibility You will develop and manage business and web applications in the AWS Cloud. Together with your team, you will oversee the entire value chain (YBYO): architecture, infrastructure, development, testing, security, deployment, monitoring, on-call duties, and maintenance. Product Focus: Monetization Processes and Services You will develop services for the representation and billing of our business models. Key components include the ERP system Odoo, internal data management tools, and interfaces to Salesforce and SAP. Innovative business models require innovative solutions; hence, you will closely collaborate with stakeholders such as our accounting, sales teams, account management, and other cross-functional engineering teams. Technical Excellence You will actively contribute ideas for process improvements, emphasize high code quality, and engage in continuous personal development – we support you with various training opportunities.

As a Team Lead Java Engineer in our Remarketing department, you will spearhead architecture, solution design, development, quality assurance, deployment, monitoring, and maintenance within our service-oriented platform. This platform currently features over 300 RESTful microservices. You and your team will take ownership of a selection of applications and services.Leverage your hands-on experience and proactive attitude to tackle complex challenges effectively, providing innovative solutions and technical guidance grounded in your robust technical expertise.Take charge of the professional growth and development of your team, fostering an environment where everyone strives to improve daily.Recruit top-tier talent, exemplify leadership, and mentor your team members to push boundaries and achieve excellence.

About the Role MongoDB is looking for a Senior Solutions Architect to join the Pre-Sales team in Berlin. This group brings together technical sales professionals, software architects, and developers who help customers succeed with MongoDB’s data platform. The team partners closely with sales executives to understand customer needs and deliver technical solutions that fit those requirements. What You Will Do Guide clients in designing and implementing reliable, scalable systems using MongoDB’s data platform Work directly with a range of customers, from startups to large enterprise IT teams Collaborate with sales colleagues to address customer challenges and help drive business growth Act as a trusted advisor, supporting customers through software design, deployment, and operational best practices Who We’re Looking For Experienced technologists who enjoy working with customers and solving real-world problems Comfortable taking ownership of customer outcomes and technical alignment Based in Berlin and able to support a hybrid working model Location This position is based in Berlin and follows a hybrid work approach.

Join Our Team as a Solutions Architect!At Lever Professional Services, we are seeking a highly skilled Solutions Architect to assess, design, and deliver tailored solutions that cater to the distinct needs of our clients. As the landscape of technical ecosystems evolves, our customers rely on us to seamlessly integrate Lever with their diverse technology stacks, create custom automation across systems, and facilitate customer-led development through our APIs. Our bespoke solution projects are multifaceted, often involving collaboration with cross-functional teams from both our organization and our clients. We are looking for a unique blend of technical expertise, innovative problem-solving abilities, and business acumen to drive these projects successfully.