Why You Should Join the PLS (Profiles, Lists and Segments) Team:

The PLS team is responsible for building and scaling the core customer data experiences at Klaviyo — profiles, lists, and real-time segments. We own the tools that let customers understand who their users are, group them into meaningful audiences, and keep those audiences up to date as new data flows in. Our work underpins how customers target, personalize, and measure every message they send, making this product area core to Klaviyo’s continued success.

As a Senior Software Engineer on the team, you’ll play a key role in designing and building scalable systems that power how customers manage and activate their data. Partnering closely with product managers, data scientists, and other platform teams, you’ll help define scope, translate complex data and UX problems into practical implementations, and build intuitive workflows that give customers confidence in their audiences. This role leans frontend, with a strong focus on crafting thoughtful, reusable components and seamless user experiences using technologies like TypeScript, React, Python, and Django. There are ample opportunities for growth given the scope of this role and the team’s central role in Klaviyo’s product.

How You Will Make a Difference:

• You will be a core member of the PLS team, working on impactful customer-facing features that will make our product the best in the industry.
• You will work on creating easy-to-use editors that are highly performant.
• You will work closely with Product, Design, and Data Science to provide the best experience for our customers.
• You will mentor team members and drive initiatives that help the team learn new skills.

Who You Are:

• 5+ years of experience in full-stack development with strong hands-on skills in React, Redux, JavaScript, HTML, and CSS, along with familiarity with general web best practices.
• Has a track record of delivering and shipping work powered by or accelerated through AI.
• Experience conducting code reviews and running a robust testing cycle using automated testing practices and frameworks, including end-to-end and integration tests (e.g., cypress, pytest).
• Experienced with RESTful and GraphQL APIs, and evolving APIs and data models to support product success.
• You take ownership of your work—from requirements and edge cases to implementation and testing—and are motivated by solving tough problems with others.
• Proven track record of leading complex, multi-quarter projects involving cross-team collaboration and being accountable for their outcomes

Technologies We Use (not exhaustive):

• React, TypeScript, Redux
• Python, Django
• Amazon Web Services (EC2, RDS, Aurora, S3, etc.), Terraform, and other DevOps tools
• MySQL, RabbitMQ, Redis, ProxySQL

We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025.

Please see the independent bias audit report covering our use of Covey here

The Role

Akoya is seeking a Principal Software Engineer (Frontend) to lead the next generation of our user experiences and frontend architecture. This role is ideal for an experienced engineer who brings a high bar for design quality, a deep mastery of modern JavaScript and React, and the ability to drive technical strategy across complex products. You combine impeccable attention to detail with strong communication skills and a passion for building elegant, scalable, and intuitive user interfaces that directly empower our customers.

As a Principal Engineer, you will:

• Lead the design and implementation of Akoya’s core frontend architecture, setting standards for code quality, performance, accessibility, and maintainability.
• Drive the evolution and modernization of existing frontend systems, ensuring legacy components remain reliable while guiding their transition toward more scalable, performant, and maintainable patterns.
• Write clean, well-structured, and well-documented code in React, TypeScript/JavaScript, and modern frontend tooling.
• Partner closely with product managers, designers, and backend teams to define requirements, shape features, and deliver polished, high-quality user experiences.
• Debug and resolve complex production issues across the frontend stack, delivering reliable and resilient interfaces.
• Elevate the engineering organization via mentorship, architectural guidance, and code review, enabling teams to deliver at a high level.
• Champion frontend best practices—including performance optimization, component system design, and UX consistency—across the organization.

Qualifications

Not all applicants will have skills that match a job description exactly. Akoya values diverse experiences in other industries, and we encourage everyone who meets the required qualifications to apply. While having “desired” qualifications make for a strong candidate, we encourage applicants with alternative experiences to also apply. If your career is just starting or has not followed a traditional path, do not let that stop you from considering Akoya. We are always looking for people who will bring something new to the table!

Required Experience/skills

• 10+ years of professional frontend engineering experience, building and maintaining production web applications at scale.
• Expert-level proficiency in React and modern JavaScript/TypeScript, including state management patterns, hooks, component architecture, and performance tuning.
• Demonstrated experience designing large-scale, modular frontend systems (design systems, component libraries, multi-app architectures, microfrontends, etc.).
• Strong understanding of HTML5, CSS3, responsive design, accessibility standards (WCAG), and web performance best practices.
• Proven ability to lead technical projects autonomously, drive architectural decisions, and communicate complex concepts clearly.
• A strong sense of customer empathy and a track record of delivering intuitive, high-quality user experiences.
• Experience collaborating deeply with product, design, and backend teams to define and deliver cross-functional initiatives.

Preferred Experience/skills

• Experience with frontend build and performance tooling (Webpack, Vite, Babel).
• Background working with design systems or UI component libraries (e.g., Material UI), and partnering with design teams on UX strategy.
• Experience with testing frameworks (Jest, Testing Library, Cypress, Playwright).
• Familiarity with cloud-based environments, CI/CD pipelines, and production observability tools.
• Understanding of backend API design and integration patterns (REST, GraphQL).
• Experience operating within AWS or similar cloud environments.
• Experience with state management in React, such as React Context, custom hooks, or Redux/Redux Toolkit.

Akoya is an equal-opportunity employer.

This remote position is only available to individuals living in the greater Boston, MA, New York City, NY and Raleigh, NC areas. Candidates who do not live within these areas will not be considered for this role.

The Opportunity

If you've worked alongside hardware teams, you know the damage that results from a missed change request or critical context that was never relayed to the right person. Reflow exists to close that gap. We're building the first AI-powered platform purpose-built for hardware product development, one that listens across the tools teams already use, maintains a structured picture of every program, and proactively coordinates across disciplines when things inevitably change.

This is a ground-floor opportunity for a hands-on frontend engineer to shape the user experience of a high-potential product with the support of a parent company leading innovation in engineering and manufacturing.

Who We're Looking For

We're seeking a frontend engineer who cares deeply about building interfaces that are fast, intuitive, and delightful. The ideal candidate has shipped production React applications and has strong opinions on component architecture and design systems. You should already be using AI coding tools like Cursor, Copilot, or Claude to accelerate your work, with excitement about building the product that finally replaces the spreadsheets and status meetings that hardware teams have been stuck with for decades.

This senior engineer will work alongside our engineering team and head of product to build the interfaces through which users manage structured engineering artifacts (requirements, project plans, dependencies), interact with ambient AI agents, and get real-time transparency into project health across disciplines. The role is hands-on - you will be coding daily while contributing to frontend architecture decisions and helping grow the design system as we scale.

What You'll Do

Your day-to-day responsibilities will include:

● Building production-grade React applications with TypeScript

● Developing and maintaining a shared component library

● Building rich interfaces for structured engineering data: requirements with traceability, phase/gate tracking, dependency graphs, task boards with discipline tags, and version-controlled project plans

● Building interfaces for AI agent interactions including streaming chat, proactive coordination alerts, and AI-generated status summaries and deliverables (proposals, SOWs, reports)

● Implementing portfolio-level dashboards for engineering leaders and executives showing cross-project cost, schedule, and risk

● Writing well-tested code with unit and end-to-end tests

● Collaborating with backend engineers on API integration and client SDK usage

● Contributing to frontend architecture decisions, code reviews, and engineering best practices

Technical Requirements

Must Have:

● 5+ years building production web applications, with 3+ years focused on React

● Demonstrated proficiency using AI coding tools (Cursor, Copilot, Claude, etc.) to accelerate development

● Expert-level expertise with React, TypeScript, and modern JavaScript

● Strong experience with component-driven development, design systems, and tools like Storybook

● Proficiency with CSS frameworks (Tailwind CSS preferred) and responsive design

● Experience with modern build tools (Vite, esbuild, or similar)

● Understanding of API integration patterns (REST, OpenAPI, generated clients)

● Ability to balance rapid iteration with maintainable, well-tested code

Highly Valuable:

● Have worked in early-stage 0 to 1 startup environments

● Familiarity with hardware development, engineering workflows, or project management processes

● Experience building UIs for AI/LLM-powered features (streaming responses, chat interfaces, structured AI output)

● Familiarity with headless component libraries (Base UI, Radix, Headless UI)

● Background in data visualization or dashboard-heavy applications

● Understanding of authentication/authorization patterns (OIDC, JWT)

● Experience with end-to-end testing frameworks (Playwright, Cypress)

● Background in B2B SaaS platforms, project management tools, or technical collaboration products

What We Offer

Real Impact: The opportunity to build purpose-built tooling for an entire industry that has never had it

Customer Access: Direct exposure to hundreds of real hardware projects annually through Re:Build's engineering and manufacturing companies

Technical Growth: Hands-on work with cutting-edge AI technologies solving novel technical challenges

Autonomy: Backed by Re:Build while operating with startup independence

Benefits: Full health/dental/vision, bonus program, generous 401K, paid time off, annual learning stipend

Equity & Growth: Participation in Re:Build's LTIP equity program and opportunity for founder equity in potential spin-out

Compensation & Location

Location: Remote-first, with preference for candidates in Boston, Seattle, Los Angeles, or other cities with Re:Build offices

Compensation: Base salary range of $165,000 to $215,000 with performance bonus and long-term incentive plan offered. Potential equity stake under independent spinout scenario.

Please note this role is restricted to US citizens or lawful permanent residents only due to exposure to export controlled information

About Re:Build Manufacturing

Re:Build Manufacturing is a growing family of industrial and engineering businesses combining enabling technologies, operational superiority, and strategic M&A to build America's next generation industrial company. At Re:Build we deploy deep expertise in engineering, operations management, and technology to supercharge the performance of our member companies. We harness deep professional expertise and a candid, principled operating culture to drive differentiated outcomes. Ours is a fast-paced environment where individuals can stretch and be challenged to pursue their fullest potential.

Re:Build was founded to pioneer a profitable model for the revitalization of US manufacturing. We've assembled a powerful set of complementary capabilities and lines of business that enable us to pursue a wide range of end markets. Our acquired businesses are grounded in build-to-print and by-the-hour engineering and design services, and we're using their combined expertise to migrate to increasingly sophisticated program development and production, as well as the generation of our own products. Our unique set of capabilities lend themselves to highly complex systems and products, and we offer customers a range of services including product and systems design, automation, fabrication, assembly, and large volume contract manufacturing. Our customers span a wide array of industries including aerospace, defense, mobility, healthcare, pharma, biotech, clean tech, chemicals, energy, lifestyle, food production, and industrial equipment.

We want to work with people that reflect the communities in which we operate

Re:Build Manufacturing is proud to be an Equal Employment Opportunity and Affirmative Action employer. We do not discriminate based upon race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, veteran status, marital status, parental status, cultural background, organizational level, work styles, tenure and life experiences. Or for any other reason.

Re:Build is committed to providing reasonable accommodations for qualified individuals with disabilities in our job application procedures. If you need assistance or an accommodation due to a disability, you may contact us at accommodations.ta@ReBuildmanufacturing.com or you may call us at 617.909.6275.