Principal / Senior Software Engineer
Flagship Pioneering
September 22, 2026
Full-time
Remote friendly (Cambridge, MA)
Worldwide
IT
Role: Senior/Principal Software Engineer leading AI-enabled consumer application development, focusing on scalable, secure cloud solutions. Responsibilities: design and develop customer-facing features across full-stack, collaborate with product, design, and research teams to translate needs into impactful features, own features from discovery through iteration, manage release processes, leverage analytics to improve products, design scalable architectures using AWS, and ensure data security and compliance. Requirements: 5+ years in software development with application building experience, proficient in Python and AWS (ECS, S3, Lambda), demonstrated ability to build scalable, efficient applications, strong communication skills. Preferred: experience with large language models (LLMs), AWS certifications (e.g., Solutions Architect), building with AWS CDK and Typescript, security best practices for SaaS. High-value: early-stage AI health/wellbeing platform, cloud-based infrastructure, cross-functional collaboration, entrepreneurial environment; remote/hybrid work possible, no travel specified.