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 plat