Contract Senior Software Engineer – Backend Integrations / AI Framework

Contract Senior Software Engineer (Java / Kotlin) – Attractions Connectivity

Location: Manchester, UK (hybrid, 2 days a week in the office)

Contract: Senior engineering contractor (day rate), full-time

About Booking.com & Attractions

At Booking.com, our mission is to make it easier for everyone to experience the world. The Attractions vertical is part of the Trips business unit and focuses on tours, activities and things to do at destinations worldwide. We’re building a marketplace with the world’s broadest selection of bookable experiences, tightly integrated into the Connected Trip.

About the Attractions Connectivity team

The Attractions Connectivity team is a newly formed team, responsible for the technical interface between Booking.com and our connectivity partners and direct suppliers. Our goal is to accelerate the onboarding of new providers and give internal teams a consistent, provider‑agnostic platform to build on.

Role overview

We are looking for a Contract Senior Software Engineer to help bootstrap and scale the new Attractions Connectivity team. You will:

• Lead design and implementation of backend services and integrations in a modern Java/Kotlin stack

  
  

• Take ownership of complex connectivity flows (products, availability, reservations, webhooks)

  
  

• Help define engineering standards, observability and operational practices for the new team

  
  

• Work closely with product, commercial and operations partners to turn onboarding and reliability needs into robust technical solutions

  
  

• This is a hands‑on senior role for an experienced engineer who is comfortable joining an early‑stage team, dealing with ambiguity, and steadily putting structure in place.

What you’ll do

• Design & build connectivity services

  
  

• Design, implement and evolve backend services and APIs in Java/Kotlin (e.g. Spring Boot or similar), running on Kubernetes with CI/CD.

  
  

• Integrate with third‑party provider APIs

  
  

• Build reusable connectors, templates, tooling and internal APIs to reduce the marginal engineering cost of adding new providers.

  
  

• Model provider, product and availability data in a way that supports both scale and flexibility

  
  

• Work with commercial, operations and other engineering teams to understand the end‑to‑end provider onboarding process and identify bottlenecks.

Own reliability & operations:

• Instrument services with robust logging, metrics and alerting (Grafana, Alerting, tracing) and define SLOs for key connectivity paths.

  
  

• Participate with in-hours on call leading incident diagnosis and driving follow‑up improvements and op docs.

  
  

• Improve resilience of integrations through idempotency, retries, circuit breaking, back‑pressure, and graceful degradation.

Technical leadership & collaboration:

• Break down fuzzy problem statements into clear technical designs and incremental delivery plans.

  
  

• Lead design discussions, produce clear design docs, and give high‑quality code reviews for other engineers and contractors.

  
  

• Collaborate closely with teams both within and outside of Booking to deliver engineering solutions

What you’ll bring

Essential experience:

• Strong backend engineering experience (typically 7+ years) building and operating production services in Java or Kotlin.

  
  

• Solid experience designing and consuming HTTP/REST APIs and integrating with external platforms.

  
  

• Hands‑on experience with distributed systems: concurrency, failure modes, data consistency, idempotency, retries and timeouts.

  
  

• Experience with cloud‑native development and deployment (Docker, Kubernetes, CI/CD pipelines; AWS or similar cloud).

  
  

• Good working knowledge of relational databases (e.g. MySQL) and at least one of: Kafka, other message queues, or event‑driven architectures.

  
  

• Strong focus on observability (logs, metrics, dashboards, alerts) and proven experience investigating and resolving production incidents.

  
  

• Ability to work effectively in a cross‑functional team, collaborating with product managers, EMs, and non‑engineering stakeholders.

  
  

• Clear, concise communication in English, written and spoken.

Nice to have:

• Experience with connectivity / integrations in travel, ticketing, or other marketplace domains (e.g. OTA, attractions, tours & activities, payments).

  
  

• Familiarity with attractions‑specific standards (e.g. OCTO) or similar vertical API standards.

  
  

• Previous experience in an early‑stage or “startup‑style” team within a larger organisation (helping define ways of working, tooling and patterns).

  
  

• Experience building internal tooling or portals that sit on top of backend services (no need to be a pure frontend specialist).

If you’re an experienced backend engineer who enjoys complex integrations, cares about reliability, and wants to help shape a new team from the ground up, we’d be happy to hear from you.