Sr. Backend Engineer

Sr. Backend Engineer We’re assisting an established Series B startup with their search for a sr. backend engineer to build their external booking API from scratch. Their product allows customers to access luxury hotel amenities for the day without having to book a room. The role will work onsite in the NY office Monday through Thursday and remotely on Fridays. What You’ll Do:

Design and build the external booking API for distribution partners (availability, pricing, reservation, modification, cancellation). Own correctness-critical transaction flows - ensure booking, payment, and inventory operations are atomic, idempotent, and resilient under concurrent load. Define API contracts (versioning, authentication, rate limiting, error handling) for external partner consumption. Partner with product and business teams on partner integration requirements and launch timelines. Instrument services for observability (Datadog) - latency, error rates, throughput, and business-critical alerts. Contribute to platform reliability (Redis caching, Kafka event streaming, OpenSearch indexing) across the booking domain

You have 6+ years of software engineering experience, or a track record of equivalent impact. You have designed transactional systems, built external APIs or integration platforms, and safely evolved data models in production. You understand relational modeling, concurrency, consistency, asynchronous workflows, and distributed failures. You turn complex business rules into clear boundaries, lifecycle states, contracts, and invariants. You can lead an important system as its primary builder while collaborating on foundational decisions. You care about correctness, testing, observability, and safe rollouts. You communicate directly, listen well, and improve the work of engineers around you.

Nice to haves:

Ruby on Rails experience Experience with marketplaces, reservations, inventory-constrained commerce, public APIs, or third-party booking systems