Senior Backend Engineer

Location

San Francisco

Full time

On-site

Engineering

As a Backend Engineer at Spherecast
, you will be responsible for building the backbone to scale Agnes throughout the world - our AI Supply Chain Manager that decides what to produce, where to make it, and how to move it through factories, warehouses, and channels.

This is a fast-paced, highly autonomous role for someone who can own backend systems end-to-end
: from designing data architectures to making sure user requests get processed in real time, so physical goods can flow reliably to the right place, at the right time.

You’ll work directly with the core team to turn the physical flow of goods into something as programmable as code.

If you’re a builder who thrives at the intersection of large-scale data architectures, systems engineering, and organizing messy real-world data
, this is your opportunity to shape how global brands run their supply chains.

You are a great fit if you have:

• Hands‑on experience with modern backend stack environments: FastAPI, Python, and testing frameworks such as pytest, with a track record of shipping real products.
• Claude Code, Codex, and Open Code are your best friends - you know how to parallelize instances to make sure we’re shipping 24/7, even while you sleep, and you know the ins and outs of each of them at any time.
• A track record of building full‑stack apps
  , including designing data architectures and backend systems.
• Proficiency in SQL, writing high‑performance queries despite millions of data points for even a single customer.
• System design skills - one of your biggest assets. You know how to design data architectures and systems that not only scale in the short term, but can also grow with the company with minimal human supervision.
• When it comes to engineering with your toolkit, you don’t care whether it’s a pickaxe or a shovel - you know which one to use at any time.
• Bonus: Experience building a company before, and working frontend frameworks and their testing, unstructured data ingestion systems and, Dev Ops and AWS.

Spherecast is building Agnes, the AI Supply Chain Manager for Consumer Goods.

Agnes decides what to produce, where to make it, and how to move it through factories, warehouses, and channels – simulating thousands of options in seconds and executing the best plan.

We are building Agnes to shape the physical flow of goods in the world, turning it into something as programmable as code.

When we succeed, every consumer product you touch will run on the Spherecast stack – planned in the Spherecast OS, executed over Spherecast Rails, and optimized by the shared Spherecast Network.