Senior Prompt Engineer

Trusted by more than 18,000 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.

Senior Prompt Engineer

Remote, Anywhere in North America

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 Description

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.

Job Description

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.

Primary Duties

• 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 for revenue per subscriber while maintaining or improving unsubscribe rates and sentiment baselines)
• Operate and communicate effectively across all teams leveraging AI, serving as a unifying voice for prompt quality
• Mentor prompt engineers and cross-functional contributors (PM, design, engineering) on AI interaction design
• Drive cross-team collaboration around AI behavior, safety, and user experience standards
• Stay hands-on with product teams to ship and improve AI-powered features
• Shape the roadmap for scaling prompt engineering across products and teams
• Stay current with emerging LLM techniques, tools, and practices, and drive their adoption across the organization

What We’ll Love About You

• Obsessive customer-first and animal mindset
• 8-10 years of experience in marketing technology required, with a strong preference for the ecommerce sector, AI/ML, conversational commerce
• Background in Martech Sales/Solutions Engineering, Customer Success, Marketing Strategy, or Product Management
• Deep recent expertise in LLMs and prompt engineering, with hands-on experience writing prompts and executing evals
• Proven track record of shipping 0-to-1 products
• Entrepreneurial experience and/or technical background (engineering, data science, or similar) is a bonus
• Experience defining standards, setting a bar for excellence, and mentoring others in AI interaction design, including eval creation and iteration
• Ability to balance hands-on work with leadership responsibilities (player/coach)
• Strong collaboration and communication skills, with the ability to influence across product, design, engineering, and AI teams
• Analytical and user-centered, with a track record of using data to improve prompt effectiveness
• Growth-oriented, eager to step into greater leadership as our AI footprint grows
• Strong curiosity and learning mindset about the evolving LLM ecosystem and emerging best practices

What You'll Love About Us

• Salary range of USD $135,000-$153,750 base plus equity (we do not have geo based salaries)
• High growth startup - plenty of room for you to directly impact the company and grow your career!
• Work from home (or wherever)
• Fun - We're passionate and enjoy what we do
• Competitive compensation and opportunity for equity
• Flexible paid time off
• Health, dental, vision insurance

What to expect from our hiring process:

• Intro Call: You'll hop on a quick call with the Recruiter so we can get to know you better — and you can learn a little more about the role and Postscript.
• Hiring Manager Intro: You'll hop on a quick call with the Hiring Manager so your future Manager can get to know you better — This is a great time to learn more about the team & position.
• Virtual Onsite Interviews: You'll be meeting with 2-4 team members on a series of video calls. This is your chance to ask questions and see who this role interacts with on a daily basis.
• Technical Assessment: We'll provide you with a prompt engineering challenge that mirrors real-world scenarios you'll encounter in the role.
• Final FEACH Interview: This is our interview to assess your ability to represent how you work via our FEACH values. As we build the #1 team in E-commerce, we look for individuals who embody FEACH professionally and personally.
• Reference Checks: We ask to speak with at least two references who have previously worked with you.
• Offer: We send over an offer and you (hopefully) accept! Welcome to Postscript!

You are welcome here. Postscript is an ever-evolving place of equal employment for talented individuals.

You are welcome here. Postscript is an ever-evolving place of equal employment for talented individuals.