Senior Fullstack Engineer, Customer Context - Postscript

Postscript is the AI messaging platform trusted by 20,000+ Shopify brands — including Brooklinen, Ruggable, True Classic, and Dr. Squatch. With a mission to make SMS your number one revenue-driving channel, we built the best-in-class SMS marketing platform and launched revenue-driving AI features not available on any other platform. Backed by Greylock and Y Combinator, we have been fully remote since 2018.

We are looking for a polyglot Senior Fullstack Engineer to join the Customer Context team. You’ll help build and scale the foundational services, APIs, and pipelines that power the Postscript product. This role blends strong backend engineering skills with a deep appreciation for data-intensive systems, performance, and reliability. You’ll collaborate closely with software engineers, data engineers, and product managers to help e-commerce marketers maximize revenue through best-in-class targeting and context-driven AI.

This is a high-autonomy role for engineers who are energized by ambiguity, take genuine ownership of their work, and bring a strong point of view on how to build things well without sacrificing speed or pragmatism. AI isn't a nice-to-have here — it's central to how we work. We expect our engineers to be active practitioners of AI-first development: fluent with the latest agentic coding tools, curious about emerging technologies, and constantly pushing boundaries.

This position is fully remote and can be based in the US or Canada.

What You'll Do

• Take deep ownership of systems and product areas on your team, becoming the go-to technical expert for your domain.
• Independently investigate, design, and execute solutions across distributed systems with a high degree of ambiguity.
• Architect, build, and maintain highly available, scalable REST APIs and backend services for internal and external use.
• Drive system decoupling, modularization, and technical debt reduction while balancing near-term delivery.
• Build agentically by default: leveraging concurrent autonomous agent workflows, owning output, and keeping a steady queue of aligned work moving.
• Stay at the forefront of emerging AI tooling and practices, sharing new techniques with the team to raise the baseline for engineering quality.
• Contribute to integrating AI into systems and workflows, shaping where and how AI creates leverage across the engineering org.
• Collaborate cross-functionally with product, data, and go-to-market teams via clear, proactive async communication.
• Identify and eliminate single points of failure, improving system resilience and knowledge redundancy.
• Improve engineering processes by introducing better tools, fixing workflow friction, and building high-leverage internal utilities.

What We're Looking For

• 6+ years of experience building large-scale, data-intensive backend systems and APIs.
• Active daily experience using AI coding tools (Claude Code, Codex, Cursor, Copilot, or equivalent) to maximize output.
• Proficiency in some or all of these technologies: Python, Go, Rust, React, and TypeScript.
• Deep familiarity with the AI tooling landscape: model releases, emerging agentic workflows, and evolving best practices.
• Critical thinking regarding AI output—knowing where it accelerates work, where it introduces risk, and how to verify output.
• Ability to context switch quickly across concurrent workstreams.
• Proven track record with both 0-to-1 initiatives and complex legacy systems.
• Working knowledge of event-driven distributed systems (Kafka) and distributed data processing technologies (Flink, Spark, etc.).
• Experience scaling systems under production customer load from early stages to multi-terabyte volume.
• Experience designing high-scale systems on AWS with diverse database technologies (RDBMS, OLAP, NoSQL).
• Strong relational data modeling and indexing strategies, including writing performant SQL for transactional and analytical workloads.
• Hands-on experience with Infrastructure as Code (e.g., Terraform).
• Familiarity with building and observing applications on AWS & Kubernetes using tools like Datadog or SigNoz.
• Clear, direct, and proactive communication in an async-first distributed environment.

What You'll Love About Us

• Base salary range of USD $175,000–$205,000 plus significant equity.
• High-growth startup environment with clear room for career growth.
• Fully remote work policy across the US and Canada.
• Flexible paid time off.
• Comprehensive health, dental, and vision insurance.