S23 - AI

Staff Backend Software Engineer

Location: On-site, San Francisco, CA

Salary: $225,000 - $300,000 USD

Employment: Full-time

Visa Sponsorship: Not available - US citizens and Green Card holders only

About the Role

A rapidly growing, early-stage technology company is looking for a Staff Backend Software Engineer to own and build the core backend infrastructure powering highly scalable SMS messaging.

You'll join a small, high-calibre engineering team at a company that has recently raised a $50M Series A and is expanding rapidly across enterprise, SMB, and political messaging. The platform currently delivers billions of messages per month, creating an opportunity to work on infrastructure at significant scale while having substantial technical ownership and impact.

We're looking for an engineer with strong career velocity who has experience building 0→1 products at high-growth startups, ideally from Pre-Seed through Series B. You'll thrive in an environment where engineers have significant autonomy, move quickly, and are expected to solve complex technical challenges from first principles.

Key Responsibilities

• Own and build core backend systems across routing, messaging, delivery, and automation infrastructure
• Design and ship highly scalable production services handling billions of messages per month
• Drive 0→1 product development, taking entire product surfaces from initial concept through production
• Design reliable distributed systems and queue-based architectures at significant scale
• Solve complex infrastructure challenges while moving quickly from idea to production
• Work closely with a lean, highly technical engineering team
• Make critical architectural and technical decisions as the company and platform scale
• Take end-to-end ownership of projects, from technical design through deployment and ongoing operation
• Help establish engineering practices and infrastructure that can support rapid future growth

What We're Looking For

• 6+ years of backend software engineering experience
• Strong experience working in early-stage, high-growth startups, ideally Pre-Seed through Series B
• Proven experience building products, systems, or significant technical initiatives from 0→1
• Strong understanding of distributed systems and highly scalable backend architectures
• Experience building messaging, queue-based, or asynchronous infrastructure
• Experience designing and operating reliable production services at scale
• Strong technical judgment and a pragmatic approach to solving difficult engineering problems
• Comfortable working with significant autonomy in a fast-moving environment
• Ability to move quickly without compromising engineering quality or reliability
• Excellent communication and collaboration skills

Tech Stack

• Node.js
• TypeScript
• AWS
• SQS
• Queue-based infrastructure
• Distributed backend systems

Why Join?

• Work on infrastructure processing billions of messages per month
• Own critical backend systems with significant architectural responsibility
• Build new products and systems from 0→1
• Join a small, highly technical engineering team
• Solve challenging distributed systems and infrastructure problems at scale
• Have a meaningful influence on technical direction and product development
• Join a rapidly growing company with significant funding, strong traction, and a large addressable market

About the Company

An early-stage technology company is building an AI-first communications platform designed to help organisations deliver outbound SMS messaging at scale.

The company operates in a large and rapidly expanding market, serving enterprise, SMB, and political messaging use cases. Its infrastructure already supports billions of messages per month, with the team continuing to scale the platform and expand its product offering.

The company was founded in 2023 and has raised approximately $60M in total funding, including a recent $50M Series A. The engineering organisation remains intentionally lean, giving individual engineers significant ownership and the opportunity to make a direct impact.