Senior Prompt Engineer

Location Type: Remote, Anywhere in North America Employment Type: Full-time

Company Overview

Trusted by more than 20,000 Shopify and Shopify Plus stores—like Brooklinen, Ruggable, True Classic, and Dr. Squatch—Postscript gives ecommerce brands the tools they need to run a world-class SMS marketing program.

We're on a mission to make SMS the number-one revenue channel for ecommerce merchants by delivering an easy-to-use platform where they can grow their subscriber list, develop and test their messaging strategy, deliver excellent customer service, and drive sales and loyalty—all in one place. We believe SMS is the most important marketing and sales channel of the decade, and that vision drives everything we do.

Postscript was founded in 2018 as a 100% remote organization. With more than 250 employees (and counting!), we're backed by Greylock, Y Combinator, and other top investors.

Postscript is redefining marketing for ecommerce companies. By introducing SMS as an entirely new channel for ecommerce stores to engage, retain, and convert their customer base, brands are seeing huge ROI with Postscript. Backed by Greylock, Y Combinator, and other top investors, Postscript is growing fast and looking for remarkable people to help build a world-class organization.

Position Overview

Our AI teams are expanding our capabilities to deliver innovative, AI-powered features that help merchants succeed. As the Senior Prompt Engineer, you will both lead and contribute to the development of best-in-class prompt engineering practices across our AI-powered product suite. You will set standards, guide prompt development across teams, mentor other contributors, and be hands-on in crafting high-impact prompts. This is a player/coach role with a fast-growing scope, with the opportunity to grow into a formal people leadership position as our AI product footprint expands. You will report into the Associate Director / GPM of our Messaging AI teams to start.

Think of this role as similar to a UX leader for AI interactions. You will be designing, testing, refining, and extending prompts and interaction patterns that make our AI features truly exceptional across multiple products, models, and channels.

Responsibilities

• Design, write, and optimize prompts for our LLM-powered products, ensuring high-quality, safe, and effective experiences.
• Ensure prompts perform consistently across multiple models and pass P0/P1 eval standards.
• Own the structure of our core agent and supervisor systems so they can extend to new channels, surfaces, and use cases.
• Define and improve prompt engineering standards, best practices, and review processes.
• Determine what contextual information needs to be injected into prompts and at what level of fidelity to optimize model performance across use cases - including working with engineering to design, test, and maintain structured context injection pipelines that enable high-quality outputs at scale.
• Use Freeplay for prompt evals, challenger/champion testing, and optimization.
• Set up and manage the process for testing challenger prompts against champion prompts in production (e.g., optimizing).

Requirements

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Application Instructions

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