Staff Software Engineer, Backend (Communications Platform)

Squarespace is looking for a Backend Staff Software Engineer to lead the technical direction of our Communications Platform team. The Communications Platform is a critical engine powering customer engagement across Squarespace — providing internal teams with a scalable, reliable, and secure infrastructure for delivering communications via email, push notifications and in-product messaging.

The team owns multiple interconnected production platforms that collectively send over 1.75+ million notifications per day, strategic initiatives including platform modernization, In-Product Placements, and multi-channel communication capabilities.

In this role, you’ll serve as the senior technical voice for the team — driving architecture, shaping roadmap execution, and elevating the engineering quality of a small but high-impact team. This is a hands-on role with real technical depth, paired with broad cross-functional influence.

This is a hybrid role based in our NYC office (3 days per week), reporting to the Engineering Manager of Communications Platform.

You’ll Get To…

• Drive the architecture, design, and implementation of the Communications Platform’s platforms — including Email Delivery, In-Product Notifications and Push Notifications.
• Define and own the technical strategy for platform modernization, reliability hardening, and engineering standards across backend services.
• Provide hands-on technical leadership and mentorship to a team of backend and frontend engineers, helping them grow in system design, decision-making, and ownership.
• Write high-quality Java code and stay close to execution — leading design reviews, code reviews, and architectural decisions that raise the bar across the codebase.
• Proactively identify and address systemic risks in performance, reliability, security, and operability before they become incidents.
• Serve as a key technical partner on cross-team and company-wide architecture initiatives.
• Balance short-term delivery with long-term platform health, communicating tradeoffs clearly to stakeholders and leadership.

Who We’re Looking For

• 10+ years of backend engineering experience, with significant time building and operating large-scale, customer-facing systems.
• Deep expertise in Java and backend service development, including APIs, async processing, messaging systems (ex: Kafka), and data stores (ex: MongoDB, CockroachDB).
• Strong experience with distributed systems in production — including reliability, scaling, failure modes, and observability.
• A proven track record of technical leadership at the Staff or Senior-plus level, influencing architecture across multiple teams or services.
• Experience evolving existing systems — modernizing legacy platforms, simplifying complexity, and strengthening reliability without unnecessary rewrites.<