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

Technical leadership

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

Hands-on engineering

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

Service health & 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

Roadmap & planning

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)

People & culture

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

Experience

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

Engineering depth

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

System design

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

Senior behaviors

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

Nice to have (preference)

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

Why Flights Postbook Assurance?

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