Senior / Staff Backend Software Engineer (Core Product)

Backflip•San Francisco, CA

18h

About The Position

About Backflip Mechanical design, the work done in CAD, is the rate-limiter for progress in the physical world. Despite decades of tooling, only a few million people can effectively design complex mechanical systems. But what if hundreds of millions could? What if creating something in the real world were as easy as imagining the use case, or sketching it on paper? Backflip is building a foundation model for mechanical design. We are unifying the world’s scattered engineering knowledge into an intelligent software copilot. Makers and builders use our intuitive and effortless design environment to give them the superpower of expert mechanical design skills. Our goal is to enable anyone to imagine a solution and hit “print.” Founded by a second-time CEO in the same space (first company: Markforged), Backflip combines deep industry insight with breakthrough AI research. Angel invested by Ashish Vaswani (coinventor of the transformer), and backed by a16z and NEA, we raised a $30M Series A and built a deeply technical, mission-driven team. We’re building the AI foundation that tomorrow’s space elevators, nanobots, and spaceships will be built in. If you’re excited to define the next generation of hard tech, come build it with us. The Role We’re looking for a Senior or Staff Backend Engineer to help architect, build, and ship the software backbone of Backflip’s intelligent design environment. You’ll create intuitive, high-performance mechanical design environments that connect human creativity to cutting-edge AI. You will build the APIs, services, and systems that power our interactive design environment, and ensure they meet the reliability, security, and performance expectations of enterprise customers. This is a hands-on, high-impact engineering role that blends architecture and product thinking. You’ll be a key voice in the engineering team as we define the next generation of tools to create our physical world.

Requirements

You’ve architected and operated production backend systems at scale.
You’re fluent in the modern back-end development stack and best practices (Python, RESTful APIs, CI/CD, Node.js, etc.).
You’ve built secure, multi-tenant systems used by enterprise customers.
You’re comfortable designing APIs, services, and data flows end-to-end.
You have experience with AWS databases, and you enjoy thinking about indexing, search, and vector data systems.
You’re pragmatic, product-minded, and enjoy owning features from concept to deployment.
You enjoy being flexible and doing whatever it takes to achieve the mission.
You operate with a leader’s mindset: set technical direction, create alignment and clarity with engineers and leadership, and deliver results.
You are passionate about seeing your work shape the physical world.

Nice To Haves

You have exposure to the world of mechanical engineering or related fields (aerospace, civil engineering, 3D printing, CAD, etc), e.g. through hobby builds, formal education, or prior professional work.
Experience building AI-powered or ML-backed products.
You have an interest in math, geometry, topology, rendering, or computational geometry.

Responsibilities

Architect and own the backend systems that power AI-driven design workflows for our customers, including architecture, scaling, and performance.
Deploy products to production, and iterate on them based on customer experiences and feedback.
Collaborate with the AI team, design, front-end, and product to set and deliver engineering initiatives and projects that turn our cutting-edge AI into impactful products.
Architect backend systems around AWS services, vector databases, and modern data infrastructure.
Design multi-tenant systems that support enterprise customers securely and efficiently.
Own authentication and authorization systems (RBAC, SSO, OAuth, SAML).
Improve observability through logging, monitoring, tracing, and alerting.
Own performance and scale: build APIs, indexes, and search systems that make high-dimensional data feel instant.
Own security and enterprise-readiness, including authentication / authorization.
Contribute to product direction: work with customers, design, AI, and leadership to turn technical capabilities into delightful user experiences.
(Optional but exciting): advance 3D visualization, geometry, or rendering that make engineering feel magical.