Senior Backend Engineer

Re:Build Manufacturing•Boston, MA

5d•$165,000 - $200,000•Remote

About The Position

Reflow is building the first AI-powered platform purpose-built for hardware product development. This platform aims to close the gap in communication and context relay between hardware teams by listening across existing tools, maintaining a structured program picture, and proactively coordinating across disciplines during inevitable changes. This is a ground-floor opportunity for a hands-on backend engineer to build the core services and AI infrastructure powering this platform, with the support of Re:Build, a company leading innovation in engineering and manufacturing.

Requirements

5+ years building production backend systems, with 3+ years in Python
Demonstrated proficiency using AI coding tools (Cursor, Copilot, Claude, etc.) to accelerate development
Strong experience with FastAPI or similar async Python web frameworks
Production experience with PostgreSQL, including schema design, migrations, and query optimization
Hands-on experience with task queues and background processing (Celery, Redis, or similar)
Understanding of API design, authentication patterns (OIDC/JWT), and service architecture
Experience with containerized deployments (Docker) and CI/CD pipelines
Ability to balance rapid iteration with maintainable, well-tested code
Must be a U.S. citizen or national, U.S. permanent resident (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum.

Nice To Haves

Have worked in early-stage 0 to 1 startup environments
Production experience integrating LLM APIs (Anthropic, OpenAI, etc.) and building AI-powered features with agent orchestration frameworks (LangChain, LangGraph, or similar)
Hands-on experience with GCP services (Cloud Run, Cloud SQL, Pub/Sub, Secret Manager) and Infrastructure-as-code experience with Terraform
Experience with data ingestion pipelines and ETL workflows
Background in B2B SaaS platforms, project management tools, or workflow automation products
Understanding of hardware development, engineering workflows, or project management concepts (phases, gates, dependencies)

Responsibilities

Designing and implementing RESTful APIs with OpenAPI specs and auto-generated client SDKs using SQLAlchemy and Postgres
Developing ingestion pipelines using Celery and Redis that connect to tools teams already use (file storage, messaging, email) and extract structured engineering artifacts from unstructured inputs
Building and extending agentic AI workflows using LangChain, LangGraph, and related frameworks for structured data extraction, risk detection, dependency analysis, and proactive team coordination
Integrating LLM APIs (Anthropic Claude, OpenRouter) with streaming (SSE), error handling, and cost optimization
Deploying and operating services on GCP (Cloud Run, Cloud SQL, Memorystore) with Terraform
Writing well-tested, maintainable code and participating in code reviews to establish engineering best practices