Senior Software Engineer, Front End

About the Role

The Pioneering Intelligence group at Flagship Pioneering is building intelligent software systems that integrate agentic AI with scientific reasoning to accelerate research, development, and decision-making.

We are seeking a Senior Front-End Software Engineer to design, integrate, and deploy web-based applications that enable seamless human–AI collaboration. This role is part of a bold, agentic initiative within the Pioneering Intelligence portfolio and offers the opportunity to help define the future of user-centric, LLM-enabled platforms.

About Flagship Pioneering

Flagship Pioneering is a biotechnology company that invents and builds platform companies, each with the potential for multiple products that transform human health and sustainability.

Since its founding in 2000, Flagship has launched and fostered more than 100 scientific ventures , collectively generating over $90 billion in aggregate value . Many of these companies have addressed humanity’s most urgent challenges—vaccinating billions against COVID-19, curing intractable diseases, improving human health, preempting illness, and strengthening global food security.

Flagship has twice been recognized on FORTUNE’s “Change the World” list and twice named to Fast Company’s “World’s Most Innovative Companies.”
Learn more at .

Position Summary

As a key contributor in this early-stage initiative, you will architect and implement the user experience for a new platform that leverages large language models (LLMs) and AI agents to enhance complex, high-stakes workflows.

This is a user-first, AI-augmented product — your work will transform abstract reasoning tasks into intuitive, high-performance tools that empower experts across diverse research domains.

You will lead front-end development and collaborate closely with engineers, AI scientists, product designers, and end users. This is a rare opportunity to shape a greenfield product at the intersection of usability, flexibility, and advanced reasoning.

Key Responsibilities

• Architect, develop, and maintain high-quality, testable front-end code and workflows aligned with complex scientific and analytical use cases.


• Translate user stories, wireframes, and prototypes into production-ready features emphasizing clarity, maintainability, and reusability.


• Implement responsive, accessible, and performant UIs optimized for data-rich, interactive workflows.


• Ensure security, scalability, and observability of front-end services in cloud environments (AWS).


• Design and implement user interfaces from scratch, combining strong visual design with robust engineering.


• Create and maintain scalable, consistent, and visually appealing UI components using a modern React.js stack.


• Maintain front-end quality through comprehensive testing and validation of user flows and interface behavior.


• Develop and maintain test suites (unit, integration, and end-to-end) for UI reliability.


• Apply DevOps/ GitOps practices for automated testing, deployment, and monitoring.


• Mentor engineers and scientists, driving technical quality and ensuring extensibility and performance across evolving use cases.

Qualifications

• B.S. in Computer Science, Engineering, or related field, with 6+ years of professional software development experience.


• Expertise with modern front-end frameworks and tools, including React.js, TypeScript, Tailwind CSS, Redux Toolkit, Playwright, and Shadcn .


• Strong experience with Node.js .


• Skilled in writing and maintaining comprehensive test suites ( Jest, React Testing Library, Cypress ).


• Experience with system design, performance optimization, observability, and operational excellence for parallel LLM workloads.


• Strong intuition for UX design and a passion for building intuitive, workflow-first products.


• Excellent communication skills and a collaborative mindset in fast-moving, cross-functional environments.

Preferred Qualifications

• Background in scientific domains such as biology, chemistry, or complex systems (a plus, not ).

Why Join Us

By joining this initiative within Flagship’s Pioneering Intelligence group, you will:

• Help define a new category of intelligent software tools for real-time human–AI collaboration.


• Build a greenfield product at the intersection of usability, reasoning, and scientific innovation.


• Collaborate with visionary thinkers and top-tier researchers across Flagship’s ecosystem.


• Thrive in a supportive, mission-driven culture with access to world-class technical and operational resources.


• Shape the future of AI-powered discovery in a role that combines engineering excellence with health impact.

About Flagship Pioneering

Flagship Pioneering invents and builds platform companies, each with the potential for multiple products that transform human health, sustainability and beyond. Since its launch in 2000, Flagship has originated more than 100 companies. Many of these companies have addressed humanity’s most urgent challenges: vaccinating billions of people against COVID-19, curing intractable diseases, improving human health, preempting illness, and feeding the world by improving the resiliency and sustainability of agriculture.

Flagship has been recognized twice on FORTUNE’s “Change the World” list, an annual ranking of companies that have made a positive social and environmental impact through activities that are part of their core business strategies and has been twice named to Fast Company’s annual list of the World’s Most Innovative Companies. Learn more about Flagship at .

At Flagship, we accept impossible missions to enable bigger leaps. Our core values guide us through uncertainty and toward lasting impact.

We are an equal opportunity employer . All qualified applicants will be considered for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, protected veteran status, or any other characteristic protected by law.

We recognize that great candidates often bring unique strengths without fulfilling every qualification . If you have some of the experience listed above but not all, please apply anyway. We are dedicated to building diverse and inclusive teams and look forward to learning more about your background and interest in Flagship.

Recruitment & Staffing Agencies : Flagship Pioneering and its affiliated Flagship Lab companies (collectively, “FSP”) do not accept unsolicited resumes from any source other than candidates. The submission of unsolicited resumes by recruitment or staffing agencies to FSP or its employees is strictly prohibited unless contacted directly by Flagship Pioneering’s internal Talent Acquisition team. Any resume submitted by an agency in the absence of a signed agreement will automatically become the property of FSP, and FSP will not owe any referral or other fees with respect thereto.

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The salary range for this role is $108,000 - $176,000. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Pioneering Intelligence currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Pioneering Intelligence's good faith estimate as of the date of publication and may be modified in the future.