Sr. Software Engineer

Harnham; New York (NY); Hybrid; USD 190,000 - 210,000; Full time

Job summary

Harnham in New York City Hybrid is seeking a Senior Backend Engineer to lead the development of a mission-critical external API platform powering partner integrations and transactional bookings.

You will design scalable backend systems, own API strategy, and shape architecture with senior leadership. This hands-on role offers significant ownership and a path toward Staff-level growth through technical impact.

Qualifications

• 6+ years of backend, platform, or software engineering experience.
• Proven experience designing and shipping production-grade transactional systems.
• Strong experience building APIs, integrations, or platform services.
• Experience with distributed systems and cloud-based architectures.
• Hands-on development with Ruby, Java, Python, Go, C#, or similar.
• Experience with databases and scalable backend infrastructure.

Responsibilities

• Design, build, and maintain external APIs used by strategic partners and automated systems.
• Own API architecture, data modeling, and backend technical decisions.
• Develop scalable transactional systems supporting bookings, inventory, modifications, and cancellations.
• Create reusable integration patterns and frameworks for partner connectivity.
• Collaborate closely with senior engineering leadership on platform architecture.
• Build highly available and reliable backend services on AWS.
• Improve platform performance, observability, and operational excellence.
• Contribute to long-term engineering strategy and system scalability.

Skills

Backend engineering

API design

Distributed systems

AWS

Ruby/Java/Python/Go/C#

Job description

Senior Backend Engineer (API Platform)

Location: New York City, NY (Hybrid)

Pay: $190,000 - $210,000 Base Salary + Equity

About the Role

A fast-growing consumer technology company is seeking a Senior Backend Engineer to lead the development of a mission-critical external API platform that powers partner integrations and transactional booking experiences. This individual will play a key role in designing scalable backend systems, owning API strategy, and building the foundation for future integrations and automation capabilities. This is a highly visible, hands-on engineering role with significant ownership over architecture, data modeling, and platform design. The position offers a path toward Staff-level growth through technical impact and leadership.

Responsibilities

• Design, build, and maintain external APIs used by strategic partners and automated systems.
• Own API architecture, data modeling, and backend technical decisions.
• Develop scalable transactional systems supporting bookings, inventory, modifications, and cancellations.
• Create reusable integration patterns and frameworks for partner connectivity.
• Collaborate closely with senior engineering leadership on platform architecture.
• Build highly available and reliable backend services on AWS.
• Improve platform performance, observability, and operational excellence.
• Contribute to long-term engineering strategy and system scalability.

Must Have Qualifications

• 6+ years of backend, platform, or software engineering experience.
• Proven experience designing and shipping production-grade transactional systems.
• Strong experience building APIs, integrations, or platform services.
• Experience with distributed systems and cloud-based architectures.
• Hands-on development experience with backend technologies such as Ruby, Java, Python, Go, C#, or similar.
• Experience working with databases and scalable backend infrastructure.