Senior Software Engineer, Backend

About the Role

We're looking for a Senior Backend Engineer to help build and scale the systems behind Posh's platform. You'll take ownership of backend services already running at real scale, with organizers and attendees on the other end of everything you ship.

This is a hands-on IC role. You'll design APIs and services, make architecture calls that hold up under load, and push code quality up across teams beyond your own. You'll also mentor engineers earlier in their careers.

This is an in-person role at our New York City office in SoHo, 5 days a week onsite.

Key Responsibilities

• Build and maintain the services and APIs that power Posh's platform, writing production code daily.
• Take end-to-end ownership of the backend systems you work on, from design through deployment and on-call.
• Address performance and reliability issues as usage grows, evolving systems already in production rather than designing around problems on paper.
• Instrument what you build and design security in from the start rather than adding it later.
• Build data models and pipelines that give organizers and the business actionable insight.
• Contribute to design reviews and code review outside your immediate scope, and weigh in on technical decisions that affect other teams.
• Mentor engineers earlier in their careers through code review, pairing, and direct feedback.
• Participate in technical interviews and calibration.

Ideal Candidate

• 5+ years of backend engineering experience, with a track record of shipping production systems in fast-paced environments.
• Deep expertise in backend fundamentals: APIs, data modeling, distributed systems, event-driven architecture.
• Proficient in technologies relevant to our stack (e.g., Java, Node.js, PostgreSQL, MongoDB, AWS or similar technologies).
• Experience with Infrastructure as Code (e.g., Terraform) and deploying containerized applications.
• Has scaled systems operationally, not just designed them on paper - you've watched performance regress under load and evolved architecture that was already live.
• Pragmatic about technology choices, and able to defend the tradeoffs you make.
• Communicates technical tradeoffs clearly to engineers, product, and business stakeholders.
• Experience at a consumer, social, or marketplace company is a plus.

• When applying, please include links to your GitHub profile or a portfolio of past projects.
• This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation and training.