Java Senior Software Engineer, K4B Directs

KAYAK
Vilnius Office, Lithuania
Hybrid

Who this role is best for

Best suited to Java backend developers with strong supplier integration experience working in the travel technology domain.

Best fit for

  • Candidates with a background in Java backend systems and experience in integrating with third-party travel suppliers
    — “Significant hands-on experience with Java, including designing and operating production backend systems”
  • Individuals who have led end-to-end projects and mentored junior engineers in a collaborative environment
    — “A track record of leading projects end to end and supporting the growth of other engineers”
  • Professionals comfortable with using AI coding tools as part of their daily workflow
    — “Use AI coding tools as part of your day-to-day workflow”

Things to consider

  • Requires at least three days per week in the Vilnius office despite flexible work arrangements
    — “This role requires working from our Vilnius office at least 3 days per week”
  • Candidates must demonstrate fluency in English for direct communication with partners
    — “Fluent English communication skills”

How to stand out

  • Highlight experience with handling API quirks and failure modes in your resume and interviews
    — “Build and evolve integrations with third-party APIs (SOAP/XML, REST, and proprietary protocols), handling their quirks, rate limits, and failure modes”
  • Emphasize your ability to own integration quality and resolve production issues independently
    — “Own the quality and reliability of live integrations — monitoring them, diagnosing production issues, and handling gaps between a supplier's documentation and its real behavior”
  • Showcase your experience in onboarding new partners or suppliers onto existing platforms
    — “Experience onboarding new partners or suppliers onto an existing platform”
Pace · SteadyCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

  • Lead the design and delivery of new direct supplier integrations
Typical background
Significant hands-on experience with Java

Skills & requirements

Required

JavaSpring FrameworkSQL DatabasesThird-party System IntegrationOnboarding New Partners Or SuppliersLeading Projects End To EndSupporting The Growth Of Other Engineers

Preferred

AI Coding ToolsAi-assisted Development

Stack & domain

JavaSpring FrameworkSQL DatabasesThird-party SystemsOnboarding New Partners Or SuppliersLeading Projects End To EndSupporting The Growth Of Other EngineersAI Coding ToolsFluent English Communication SkillsFinanceTravel

About the role

Original posting from KAYAK via Ashby

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.

At KAYAK for Business (K4B), we're building the future of corporate travel technology — and the engineering teams behind it are at the heart of that mission. Our K4B engineering team in Lithuania is growing, and we're looking for a Senior Java Backend Developer to help design, build, and own our direct supplier integrations. The Direct team connects K4B straight to airlines and other travel suppliers, bringing business travelers content, fares, and services that go beyond what traditional channels offer, across search, booking, and servicing. You will help shape the team's technical direction, take on some of our hardest integration and reliability problems, and support other engineers as they grow.

This role requires working from our Vilnius office at least 3 days per week.

IN THIS ROLE YOU WILL:

  • Lead the design and delivery of new direct supplier integrations, from reading partner documentation to production rollout.
  • Own the quality and reliability of live integrations — monitoring them, diagnosing production issues, and handling gaps between a supplier's documentation and its real behavior.
  • Evaluate the user and business value of work before committing to build, and track success metrics after release.
  • Build and evolve integrations with third-party APIs (SOAP/XML, REST, and proprietary protocols), handling their quirks, rate limits, and failure modes.
  • Design for suppliers that differ widely in protocols, data models, and reliability, while keeping our own model clean and consistent.
  • Act as a point of contact with partners on integration issues: investigate problems, agree on solutions, and follow tickets through to resolution.
  • Contribute to technical decisions: write design documents, review architecture and code, and help set standards for quality and testing.
  • Support mid-level and junior engineers through code reviews, pairing, and technical guidance, and work with product, QA, and partner teams on scoping and rollout.
  • Use AI coding tools as part of your day-to-day workflow — AI-assisted development is a normal part of how our team works.

PLEASE APPLY IF YOU HAVE:

  • Education in Computer Science or a related field, or equivalent practical experience.
  • Significant hands-on experience with Java, including designing and operating production backend systems.
  • Strong experience with the Spring framework and SQL databases.
  • Experience integrating with third-party systems and working directly with their providers on communication, troubleshooting, and ticket escalation.
  • Experience onboarding new partners or suppliers onto an existing platform.
  • A track record of leading projects end to end and supporting the growth of other engineers.
  • Fluent English communication skills.
  • Comfort working in a hybrid model, with at least three office days per week.

BONUS SKILLS:

  • Experience with airline direct-connect or NDC APIs.
  • Knowledge of the travel domain: fares, offers and orders, ancillaries, ticketing.
  • Experience with API certification or supplier testing programs.
  • Familiarity with AI coding tools and interest in using them to accelerate development.

BENEFITS AND PERKS

  • Work from (almost) anywhere for up to 20 days per year
  • Funds for your career growth
  • Access to thousands of on-demand e-learnings
  • Generous additional Health Insurance
  • Flexible sick time off
  • Additional financial support for your sick leave
  • Additional day off on your birthday
  • Company-wide vacation week once a year (winter holidays)
  • Additional financial support during parental leave
  • Free lunch twice a week and daily snacks at the office
  • Free yoga twice a week
  • Paid volunteering time
  • No meeting Fridays
  • Office and team events such as summer camp, KAYAK birthday, winter party and more!
  • Company-paid therapy sessions through SpringHealth
  • Company-paid subscription to HeadSpace
  • Internal Communities

COMPENSATION

Senior Java Backend Developer salary consists of three elements:

Base pay: from 3330 EUR up to 6660 EUR gross monthly.

In addition:

  • Significant yearly bonuses, approx 10 percent of annual salary
  • Booking Holdings RSU (Restricted Stock Units) package, worth [amount] gross, with possibility to receive yearly refreshes

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.

#LI-MP1

Source: KAYAK careers (Ashby)

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