Senior Software Engineer, K4B

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

Benefits offered by this job

Remote work flexibility

Mental health support

Parental leave

Vacation 6 weeks

Lunch on site

Pension plan

Public transport subsidy

Bike leasing program

Team events

Career development budget

Job summary

Kayak in Berlin seeks a senior Java backend developer to implement new features and maintain our travel search and booking technology. You will join a high-powered team that handles integrations with over 200 partners and serves millions of users daily.

Expect to own designs from concept to deployment, participate in code reviews, and help drive scalable architectures for KAYAK for Business. On-site at our Friedrichshain office is expected three days a week.

Qualifications

• Bachelor's degree or higher in Computer Science or related field.
• 6+ years of experience in JAVA and Spring ecosystem.
• Hands-on experience with SQL and NoSQL databases.
• Strong English communication skills.
• Ability to design and implement engineering initiatives.
• Travel domain experience and GDS integration are a plus.

Responsibilities

• Optimize search and booking logic for the world’s largest corporate clients.
• Build and maintain high‑performance integrations with third‑party APIs.
• Take ownership of designs from concept to deployment with quality and performance.
• Participate in code reviews and architectural steering for modular, reusable services.

Skills

6+ years Java

Spring (Spring Boot)

SQL

NoSQL

English proficient

GDS knowledge

System design

Education

Bachelor's degree in CS or related field

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 strongJava backend developerto 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

Please apply if you have:

• 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.