Principal Software Engineer - Agentic Platform

Flagship Pioneering, Inc.; Cambridge (MA); On-site; USD 188,000 - 258,000; Full time

Job summary

Flagship Pioneering, Inc. is seeking a Principal Software Engineer to own the durable agentic platform that powers autonomous scientific workflows.

You will architect the end-to-end orchestration layer, set standards, and mentor cross-disciplinary teams of AI scientists, engineers, and domain experts, turning frontier agent patterns into reusable infrastructure. The role blends hands-on architectural leadership with production-scale delivery, focusing on reliability, cost-efficiency, and

Qualifications

• B.S. or M.S. in Computer Science, Engineering, or a related field, with 10+ years of professional software development experience.
• Demonstrated track record architecting and maintaining large-scale distributed systems in production at technology companies.
• Deep expertise in workflow orchestration and event-driven architecture, including stateful execution, idempotency, durable retries, and replay.
• Strong cloud-native engineering on AWS with infrastructure-as-code, containerization, and autoscaling.
• Proven ability to take systems from prototype to hardened, observable, operationally excellent production.
• Experience designing SDKs, APIs, and data contracts that serve multiple downstream teams.
• Excellent communication skills and the ability to build organizational consensus around platform decisions.
• Collaborative and empathetic working style: listens to understand the needs of scientists, engineers, and downstream teams, and leads through influence.
• Proven track record setting technical strategy and direction for a growing engineering organization, and mentoring engineers in a fast-moving environment.

Responsibilities

• Own the agentic platform end to end, from research prototype to production, building the durable orchestration layer for long-running, multi-stage scientific workflows.
• Architect workflow orchestration, evaluation frameworks, and event-driven distributed systems that deliver scale, resilience, and reliability.
• Define SDK abstractions and API contracts between model and agent outputs and downstream consumers, decoupling rapid model iteration from product stability and reducing integration friction across teams.
• Deliver infrastructure-as-code reference implementations (AWS CDK, Terraform, containerized services) and transform exploratory AI proof-of-concepts into hardened, reusable patterns adopted across product domains.
• Own platform cost-efficiency and scalability while preserving the performance and accuracy that our experiments and end users require.
• Explore and template agent design and deployment patterns, and set technical standards, code quality, and architectural direction for the platform.
• Partner across teams to align on integration points, dependency timelines, and delivery, and mentor engineers and scientists.

Skills

Distributed systems

Cloud-native engineering

Workflow orchestration

APIs & SDK design

Architectural leadership

Mentoring engineers

Communication skills

Agentic AI knowledge

Education

B.S./M.S. in Computer Science or Engineering

Tools

AWS

Terraform

CDK

Containerization

LangChain / LangGraph / PydanticAI

Anthropic / OpenAI / Vertex AI / Bedrock

Job description

ABOUT PIONEERING INTELLIGENCE

Pioneering Intelligence builds on Flagship Pioneering’s legacy of founding cutting-edge science and computational ventures, harnessing recent advances in AI, machine learning, and data to accelerate fundamental research and create a portfolio of AI-first companies. As part of Flagship’s integrated model of science, entrepreneurship, and capital, it transforms breakthrough ideas into world-changing companies, elevating the AI advances happening across the ecosystem in human health, sustainability, and beyond.

The Role

The Pioneering Intelligence group at Flagship Pioneering is building intelligent software systems that integrate agentic AI with scientific reasoning to accelerate discovery and decision-making. At the center of this effort is a new autonomous research platform. It supports autonomous AI systems that reason over complex biological problems.

We are seeking a Principal Software Engineer to own theunderlyingagentic platform: the durableorchestration layer on which long-running, multi-agent, multi-model scientific workflows run reliably.

This is a hands-on architect role for a senior engineer who has built and operated distributed systems at scale and wants to take agentic AI from research to production. You will set the technical foundation and standards for the platform, work shoulder-to-shoulder with AI scientists, engineers, and domain experts, and turn frontier agent patterns into reusable, dependable infrastructure.

Key Responsibilities

Own the agentic platform end to end, from research prototype to production, building the durable orchestration layer for long-running, multi-stage scientific workflows. Architectworkflow orchestration, evaluation frameworks, and event-driven distributed systems that deliver scale, resilience, and reliability.

• Define SDK abstractions andAPIcontracts between model and agent outputs and downstream consumers, decoupling rapid model iteration from product stability and reducing integration friction across teams.
• Deliver infrastructure-as-code reference implementations (AWS CDK, Terraform, containerized services) and transform exploratory AI proof-of-concepts into hardened, reusable patterns adopted across product domains.
• Own platform cost-efficiency and scalability while preserving the performance and accuracy that our experiments and end users require.
• Explore and template agent design and deployment patterns, and set technical standards, code quality, and architectural direction for the platform.
• Partner across teams (modeling and agent teams, product) to align on integration points, dependency timelines, and delivery, and mentor engineers and scientists.

Professional Experience & Qualifications

• B.S. or M.S. in Computer Science, Engineering, or a related field, with 10+ years of professional software development experience.
• Demonstratedtrack recordarchitecting andmaintaininglarge-scale distributed systems in production attechnology companies.
• Deepexpertisein workflow orchestration and event-driven architecture, including stateful execution, idempotency, durable retries, and replay.
• Strong cloud-native engineering on AWS with infrastructure-as-code, containerization, and autoscaling.
• Proven ability to take systems from prototype to hardened, observable, operationally excellent production.
• Experience designing SDKs, APIs, and data contracts that serve multiple downstream teams.
• Excellent communication skills and the ability to build organizational consensus around platform decisions.
• Collaborative and empathetic working style: listens to understand the needs of scientists, engineers, and downstream teams, and leads through influence.
• Proventrack recordsetting technical strategy and direction for a growing engineering organization, and mentoring engineers in a fast-moving environment.

Preferred Qualifications

• Hands-on experience with agentic AI and orchestration frameworks (e.g.,PydanticAI,LangGraph,LangChain,CrewAI,AutoGen).
• Experience integrating LLMs and model platforms, including Anthropic, OpenAI, Vertex AI, and Amazon Bedrock, and building evaluation and feedback-loop frameworks for agentic systems.
• Familiarity with sandboxed code executionand agent harness development.
• Experience withLLMobservability and monitoringtooling and cost-governance / FinOps for AI infrastructure.
• Background in scientific domains such as biology, chemistry, or complex systems (a plus, notrequired).

Why Join Us

By joining the Agentic AI team within Flagship’s Pioneering Intelligence group, you will:

• Own the platform foundation for a category-defining autonomous scientific reasoning engine.
• Take frontier agentic AI from research to dependable production at scale.
• Collaborate with visionary thinkers and top-tier researchers across Flagship’s ecosystem.
• Set the technical standards that the broader platform and product teams build on.
• Shape the future of AI-powered discovery in a role that combines deep engineering excellence with direct human-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 www.flagshippioneering.com.

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.

The salary range for this role is $188,000 - $257,500. 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.

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