Senior Software Engineer, K4B

KAYAK; Berlin; On-site; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Office in Friedrichshain

Headspace subscription

No meeting Fridays

Paid parental leave

Paid volunteer time

Development Dollars

Travel discounts

Pension plan

Public transport subsidy

Bike leasing

Team events

Free lunch

Job summary

KAYAK, part of Booking Holdings, is seeking a strong Java backend developer to implement features and maintain our world‑leading travel search and booking technology. You will be based in Berlin and work from the office at least 3 days per week, collaborating with a high‑powered team to deliver robust APIs for travel partners.

The role requires 6+ years of Java experience, Spring Boot expertise, and strong English communication. Travel domain knowledge is beneficial but not required.

Qualifications

• Bachelor's degree in CS or related field.
• 6+ years of experience with Java.
• Hands-on with Spring/Spring Boot; relational and NoSQL databases.
• Strong English communication skills.
• Ability to design engineering initiatives with minimal guidance.
• Experience in travel domain or with airline distribution is beneficial.

Responsibilities

• Optimize search and booking logic for global corporate clients.
• Build and maintain high‑performance integrations with third‑party APIs.
• Own designs from concept to deployment with code quality and performance.
• Participate in code reviews and architectural steering for modularity.

Skills

Java

Spring/Spring Boot

SQL

NoSQL

English communication

Architecture design

Education

Bachelor’s degree in Computer Science or related field

Tools

Spring ecosystem

PostgreSQL

MySQL

Redis

GDS knowledge

Job description

KAYAK, part of Booking Holdings (NASDAQ: BKNG), is the world's 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 at our core 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.

We are looking for a strong Java backend developer to implement new features and maintain KAYAK’s world-leading search and booking technology. We integrate with over 200 travel partners and link to over 500,000 hotels and 550 airlines. 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!

In this role you will be expected to work from our Berlin office at least 3 days per week.

In This Role, You Will

• Optimize search and booking logic to handle the demands of greatest global corporate clients
• Build and maintain high-performance integrations with third-party APIs (airlines, hotel and rentalcars providers)
• Take full ownership of your designs: from initial concept to deployment while maintaining high standards for code quality and performance
• Participate in code reviews and architectural steering to ensure the K4B project remains modular and reusable as KAYAK expands its enterprise footprint

Requirements

• Bachelor’s degree or higher in Computer Science or related field
• 6+ years of experience in JAVA
• Hands-on experience with the Spring ecosystem (Spring/Spring Boot) and working knowledge of relational (SQL) and NoSQL databases (e.g., PostgreSQL, MySQL, Redis).
• Strong English communication skills
• Ability to design and implement engineering initiatives with minimal guidance
• Prior experience in the travel domain is beneficial — familiarity with airline distribution and standards (GDS such as Amadeus/Sabre/Travelport, NDC) and their integration with booking/reservation systems.
• Experience with B2B systems or identity/HR integrations is beneficial — e.g., SCIM, SAML/OAuth, SSO, user provisioning/deprovisioning, and connecting HRIS/IDP platforms (Workday, Okta, Active Directory) to product services.

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 (and returns without a pile-up of work!)
• No meeting Fridays
• Paid parental leave
• Paid volunteer time
• Focus on your career growth:
  • Development Dollars
  • Leadership development
  • Access to thousands of on-demand e-learnings
• Travel Discounts
• Employee Resource Groups
• 6 weeks paid vacation + a day off for your birthday
• Free lunch 2 days per week
• Pension plan contributions
• Public transportation subsidies
• Bike leasing program
• Monthly social events, Thursday happy hours, sports teams
• An awesome office in Friedrichshain, Berlin

Inclusion

At KAYAK, we want everyone to have the space to grow, share ideas and do great work. That’s why we’re focused on hiring the best talent from all walks of life and experiences, supporting them well and making sure no one feels like they have to fit a mold to belong here.

Need any adjustments for the interview, application or on the job? No problem - just give us a heads-up. We’ve got you.