Software Engineer, Ads (Backend)

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.

In this role you will:

• Design and build backend features, from scoping through deployment and ongoing production support, with guidance from senior engineers and tech leads on more complex or ambiguous problems

• Take part in technical design reviews and architecture discussions, asking good questions and contributing ideas

• Write well-tested, readable, and maintainable code consistent with team quality standards; participate actively in code reviews, both giving and receiving feedback

• Work with product managers and commercial partners to understand requirements and deliver reliable outcomes

• Participate in on-call rotations: monitor system health, investigate production issues, and write clear bug tickets and documentation

• Look for opportunities to improve system performance, reduce complexity, and pay down technical debt in aging codebases

• Take part in sprint ceremonies — planning, refinement, retrospectives, and demos — and contribute ideas for improving team delivery

• Use AI-assisted development tools responsibly to improve productivity, code quality, and delivery efficiency

• Collaborate with engineers, data scientists, and business intelligence teams to deliver integrated solutions

• Grow your skills through mentorship, pairing, and feedback from more senior engineers

Please apply if you have:

• Experience designing, building, and operating backend systems, gained through professional roles, internships, or substantial personal or academic projects

• Working proficiency in Java or a comparable backend language

• A foundational understanding of system design and debugging, and comfort working in distributed or multi-service environments

• A collaborative working style: you communicate clearly, follow through on commitments, surface risks early, and ask good questions

• Professional proficiency in written and spoken English

• Curiosity and a willingness to learn new tools, systems, and approaches, and to challenge existing approaches with well-reasoned alternatives

You may also bring (not required — equivalent experience, training, or transferable skills considered):

• Familiarity with ad tech systems, bidding logic, or monetization infrastructure

• Experience with server-to-server data integrations or event-driven architectures

• Experience working in an agile team environment with sprint-based delivery

• Exposure to observability tooling, metrics, or production debugging workflows

A specific degree is not required. We welcome candidates from non-traditional educational backgrounds who demonstrate strong engineering fundamentals and a genuine eagerness to grow.

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

• Generous paid vacation + time off for your birthday

• 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

• Competitive retirement and health plans

• Free lunch 2 days per week

• Fun quarterly events such as boat trips, arcades, ski trips, Thursday happy hours, and more

COMPENSATION

There are a variety of factors that go into determining a salary range, including but not limited to external market benchmark data, geographic location, and years of experience sought/required. The range for this Massachusetts-based role is $110,000 - 125,000 USD, not inclusive of annual bonus and recurring RSU grants.

We offer a competitive base salary and benefits including: health benefits; flexible spending account; retirement benefits; life insurance; paid time off (including PTO, paid sick leave, medical leave, bereavement leave, floating holidays and paid holidays); and parental leave benefits.

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.