Senior Backend Engineer – San Francisco

Titles: Backend Engineer, Infrastructure Engineer

Summary

• Senior level
• Salary: up to $210,000 (varies by performance, level, and location)
• Hiring Target: 1 (Full-time, permanent)
• Location: San Francisco (Bay Area)
• Work Setup: Primarily in-office, ~60 hrs/week
• Relocation assistance: $5K–10K

Elevator Pitch

This seed-stage startup offers a unified API and streamlined platform designed for Trust & Safety teams, making it drastically faster and easier to integrate industry-leading safety tools into products. Founded by engineers from top-tier consumer technology companies’ Trust & Safety and anti-abuse teams, the platform unifies policy management, detection, enforcement, observability, and moderator workflows into one cohesive tool that logs and traces every action—so teams can build safer platforms with confidence and speed.

Tech Stack

• LLM, Next.js, TypeScript, React, Python

Must Have

• Expertise in distributed systems and real-time processing
• Fluency with big data technologies (Cassandra, DynamoDB, BigTable, or other NoSQL)
• Experience with streaming technologies (Pub/Sub, Kafka)
• Familiarity with scaling vector databases and LLMs

Must NOT Have

• Job hopping
• Significant employment gaps
• Consulting-only background

Strongly Preferred

• Knowledge of rate-limiting infrastructure
• Experience with Kubernetes or container-based environments
• Data visualization or observability-oriented products background
• Growth-stage startup experience
• Top company + top school pedigree

Insider Scoop

• Ship end-to-end features with timelines measured in hours
• Scale product across industries, pilots, demos, and new use-cases
• Build fundamentals to scale to billions of users
• Fintech/Payments/Risk/Fraud domain experience is a plus (e.g. PayPal, Stripe, Uber)
• High transaction volume systems experience at consumer scale
• Prior experience returning (“boomerang”) to top tech companies is viewed positively
• Standout keywords: Event sourcing, stream processing, Elixir, Golang, Scala, Rust

Role Description

You’re a fit if you’re:

• Serious about craftsmanship and opinionated about your work
• Experienced with big data and streaming technologies (Cassandra, DynamoDB, Kafka, Pub/Sub, etc.)
• Comfortable owning and shipping product features end-to-end
• Familiar with scaling LLMs and vector databases for world-class user experiences

Preferred Qualifications

• Rate-limiting infrastructure knowledge
• Kubernetes or container-based environments

What You’ll Do

• Ship features end-to-end with urgency
• Expand product to new industries and use-cases
• Build infrastructure capable of scaling to billions of users

Culture

• Culture of ownership, urgency, and relentless execution
• Fully in-person, San Francisco

Company Overview

The internet, mediated by opaque algorithms, is fragile and manipulatable. This startup is using AI to help rebuild an internet that’s safe enough to be free again. They apply AI agents to billions of events a day to reduce risks like spam, scams, and abuse.

Why Join

• Y Combinator–backed
• Revenue grew 15x in the past year
• Customers include Fortune 500 companies and top-tier unicorns

Perks & Benefits

• Competitive cash + equity compensation
• Unlimited PTO
• Platinum-tier medical, dental, and vision insurance
• Lunch & wellness stipend