Senior Front End Software Engineer, Retention

About the role

KAYAK, part of Booking Holdings, is a travel search engine and is looking for a Senior Front End Software Engineer for its Retention team in Kaunas. The role requires working from the Kaunas office at least 3 days per week. You will design, build and own complex frontend features end to end, from scoping and technical design through deployment, monitoring and follow-up.

Key responsibilities

• Design, build and take end-to-end ownership of complex frontend features, from scoping and technical design through deployment, monitoring and follow-up.
• Write maintainable, well-tested code and take part in code reviews, holding yourself and the team to a high standard of quality and reliability.
• Lead technical design discussions, analyze trade-offs and document decisions clearly.
• Proactively identify and address technical debt, performance issues and reliability risks.
• Mentor less-experienced engineers through code review feedback, pair programming and knowledge sharing.
• Work closely with product managers and designers to clarify requirements and surface risks early.
• Take part in agile ceremonies (sprint planning, backlog refinement, retrospectives, demos) and help improve team processes, tooling and engineering standards.
• Use AI-assisted development tools responsibly and stay current with emerging frontend technologies.

Required profile

• Demonstrated experience independently designing and delivering complex frontend features in production; equivalent experience, transferable skills or non-traditional paths are welcome.
• Ability to communicate technical ideas clearly and to give and receive constructive feedback.
• Track record of owning work through to completion, surfacing blockers early and following through without prompting.
• Fluent English and comfort in an agile, hybrid setting with at least three office days per week.
• Nice to have: experience on advertising technology, user engagement or revenue-impacting frontend products; familiarity with A/B testing or feature flags; experience mentoring engineers.

Required skills

• Strong JavaScript and TypeScript.
• Solid experience building user interfaces with a modern component-based framework such as React or similar.
• Understanding of how frontend systems interact with APIs and backend services, and experience debugging and optimizing across that boundary.
• Writing and maintaining automated tests (unit, integration or end-to-end).

What we offer

• Base pay from 3,330 EUR up to 6,660 EUR gross monthly, plus significant yearly bonuses of around 10% of annual salary.
• Booking Holdings RSU package worth 20,000 USD gross, with possible yearly refreshes.
• Work from almost anywhere for up to 20 days per year, free lunch twice a week and daily office snacks.
• Additional health insurance, flexible sick time and extra financial support for sick leave, a day off on your birthday, a company-wide winter holiday week, paid parental leave support and paid volunteering time.
• E-learning access, career growth funds, free yoga twice a week, no-meeting Fridays, company-paid therapy sessions and HeadSpace subscription.