Senior Software Engineer, Meta AI

KAYAK, part of Booking Holdings (NASDAQ: BKNG), is a leading travel search engine. With billions of queries across our platforms, we help people find their perfect flight, stay, rental car and vacation package. We’re also transforming business travel with a new corporate travel solution, KAYAK for Business. As an employee of KAYAK, you will be part of a travel company that operates a portfolio of global metasearch brands including momondo, Cheapflights and HotelsCombined, among others. From start-up to industry leader, innovation is in our DNA and every employee has an opportunity to make their mark. Our focus is on building the best travel search engine to make it easier for everyone to experience the world.

Java Senior Software Engineer

We are looking for a strong Java Senior Software Engineer to implement new features and maintain KAYAK’s AI. You will be an essential part of a high powered team that keeps all of this running smoothly – helping millions of people find the best hotels and the best ways to fly from A to B every day! This role requires commuting to the Berlin office 3 times a week.

Responsibilities

• Design, implement and maintain reliable production software for KAYAK’s travel-search and trip-planning experiences.
• Build and evolve APIs and services supporting AI-assisted search, conversational travel planning, itineraries and related user experiences.
• Investigate technical problems, assess trade-offs and choose practical solutions that improve reliability, performance and maintainability.
• Write automated tests and contribute to quality across unit, integration and end-to-end testing.
• Participate in code reviews and technical discussions, providing constructive feedback focused on correctness, clarity and maintainability.
• Work with engineers, product managers and designers to clarify requirements and deliver useful, accessible user experiences.
• Contribute to features such as ASK AI, smart filters, AI-generated hotel review summaries, Explore and related search experiences.
• Help make AI-assisted features dependable, transparent and useful to travelers.
• Learn unfamiliar systems and share knowledge with teammates through documentation, pairing and technical discussions.
• Monitor and improve production behavior through effective debugging, observability and root-cause analysis.
• Contribute to the evolution of development tools, engineering processes and delivery practices.

Qualifications

• Experience building and maintaining production software.
• Proficiency in Java or another relevant programming language.
• Familiarity with APIs, data structures and software-design principles.
• Experience testing software and investigating defects or production issues.
• The ability to explain technical decisions clearly in writing and conversation.
• The ability to take ownership of assigned work while asking for input or support when needed.
• Experience contributing to projects from design through implementation, release and maintenance.
• Equivalent practical experience is welcome in place of a specific degree or educational path.

Experience that will help you stand out

• Experience with distributed systems, search, personalization or other high-volume consumer products.
• Experience with AI, machine learning or large language model applications.
• Experience with relational databases or other structured data stores.
• Experience working on web products, mobile products or travel-related products.
• Experience improving accessibility, reliability or usability.
• Experience working with Java and Spring.
• Experience with cloud services, CI/CD pipelines and automated testing frameworks.

Benefits and Perks

• Work from (almost) anywhere for up to 20 days per year
• Focus on mental health and well-being: Company-paid therapy sessions through SpringHealth
• Company-paid subscription to HeadSpace
• Company-wide week off a year - the whole team fully recharges
• No-meeting Fridays
• Paid parental leave
• Paid volunteer time
• Focus on your career growth: Development Dollars
• Leadership developmen