Senior Software Engineer I

Role Description:

About the team

At Booking.com, technology powers every part of how travelers experience the world. The Flights Post-Booking Assurance (PBA) team owns the post-purchase journey for millions of flights customers on iOS and Android - from the moment a booking is confirmed through check-in, day-of-travel updates, schedule changes, cancellations, and rebooking.

The team owns critical surfaces: Booking Confirmation, Booking Details, Manage Booking, Cancellation, Check-in, self-serve flows, and push/email comms during day-of-travel. Our work directly reduces customer service contact rates and unlocks self-serve coverage across the post-booking funnel.

PBA is a multi-platform team (iOS, Android, backend) working in close partnership with the Post-Booking Empower team and shared platform teams across Flights and the broader Trips track.

The role

We're looking for a Senior Software Engineer who can own backend systems end-to-end, lead technical direction across multi-quarter initiatives, and raise the engineering bar for a team of ~10 engineers. You'll be the senior backend voice in the team - writing RFCs, reviewing critical code, owning service health, and partnering with PM/UX/data to shape the post-booking roadmap.

This is a hands-on senior role. You'll write code, design systems, mentor SE2s, and represent PBA at the Flights and Trips architecture forums.

What you'll do

• Own and drive multi-quarter technical initiatives in PBA - from problem framing through architecture, RFCs, and execution
• Write and present RFCs at the Flights architecture forum; get cross-team alignment on direction and dependencies
• Be the senior backend code reviewer for the team - set the bar for code quality, testing, and design

• Design and build backend services on the Post-Book stack (Java, Kafka, MySQL/Cassandra, gRPC)
• Integrate with vendors and aggregators (e.g.,suppliers, GenAI Studio, C360 events) - own the vendor relationship, technical design, and contract
• Build for scale: services run at millions of bookings/month with strict SLOs on latency and reliability

• Own SLOs for PBA backend services - monitor alerts, drive incident follow-up, and close the loop on reliability gaps
• Participate in the on-call rotation and lead incident reviews

• Translate yearly objectives into epics, sprint-ready tickets, and a multi-quarter technical roadmap
• Partner with PM, UX, data, and platform teams to sequence work against dependencies (notably ETG, Order Service, and platform changes)

• Mentor SE1/SE2 engineers - pair on RFCs, system design, and code review
• Run engineering rituals (architecture deep-dives, tech-debt grooming, RFC reviews)
• Contribute to hiring - interview panels for SSE and SE2 roles

What you bring

• 7+ years of backend software engineering experience, with at least 2+ years operating at a senior level (E5/G-equivalent or above)
• Track record of owning multi-quarter technical initiatives end-to-end - problem framing, RFC, architecture, execution, rollout
• Experience leading vendor or third-party integrations from technical scoping through production

• Strong backend fundamentals - distributed systems, microservices, API design, async/event-driven architectures
• Production experience with Java (or another JVM language); comfortable in a polyglot stack
• Data layer experience - relational (MySQL/Postgres) and NoSQL (Cassandra/DynamoDB); schema design, query optimization, consistency trade-offs
• Event streaming - Kafka or equivalent; comfortable designing event-driven flows and dealing with at-least-once semantics
• Reliability practices - SLOs, observability (Grafana/Prometheus), incident management, capacity planning

• Can architect a system from first principles for non-trivial scale - design for millions of users, define data models, reason about consistency vs. availability, plan for failure modes
• Can communicate design clearly in writing (RFCs) and in forums

• Drives clarity in ambiguous problem spaces
• Influences without authority across teams
• Raises the bar through code review, RFCs, and mentorship
• Owns the outcome, not just the task

• Flights domain background - accelerates ramp on a domain with significant supplier, fare-rule, and post-booking complexity
• Experience with GenAI / LLM-backed product integrations
• Familiarity with iOS/Android app integration patterns (the team is mobile-heavy)
• Exposure to Kubernetes, gRPC/Protobuf, distributed tracing

• Real ownership, real scale - your work touches every traveler post-purchase; a single self-serve coverage improvement removes thousands of CS contacts per week
• New problems to design, not maintenance
• new vendor integrations, first-time GenAI use case (Prepare for your trip), email migration to C360
• meaningful design surface, not maintenance
• Cross-track impact - PBA sits between Flights and the broader Trips track; senior work here is visible to multiple LTs
• Strong engineering culture - RFC-driven, data-driven, code-review-heavy; architecture forum has active senior participation across Flights