Senior Software Engineer (For independent contractors)

We're excited to announce an opening in our Experimentation Core team for a Senior Software Engineer I. This is a great opportunity to shape the platform that powers experimentation across Booking.com. WHY JOIN US? Join a high-performing team that's collaborative, diverse, and genuinely motivated. Your ideas matter here and so does the impact you'll make.

Team Scope and Impact: Our team builds and maintains the core experimentation platform - the backbone of data-driven decision-making at Booking.com. Think real-time metrics, experiment lifecycle management, and statistical frameworks used by thousands of engineers and data scientists daily.

Innovative Solutions: We work at the intersection of engineering and data science, building systems that are deeply statistical and mathematical in nature. Our stack includes Java, AWS, and modern tooling — and we actively leverage AI to accelerate our workflows. WHO ARE WE LOOKING FOR? A senior engineer who builds and owns complex, high-scale systems end-to-end. You bring excellent coding skills, strong system design judgment, and thrive in ambiguity.

You'll elevate the team through high engineering standards.

Must-haves: Top-tier coding, testing, and production ownership skills; Strong experience with asynchronous messaging and queuing systems (e.g., Kafka, SQS); End-to-end service ownership mindset (monitoring, SLIs/SLOs); Deep, hands-on Java experience; Solid understanding of security best practices as a baseline; Strong communication skills - you'll work with many stakeholders across engineering, data science, and product; Experience collaborating with data science teams or working on DS-adjacent products.

Big plus: Affinity for statistical/mathematical concepts - you don't need a Data Science background, but curiosity and patience for statistically complex products is essential; AWS, GraphQL, Perl, Flink; Experience with JavaScript. Above all, we value camaraderie, authenticity, curiosity, autonomy, and proactivity.