Senior Full Stack Engineer (Back-End)

Wordware•San Francisco, CA

2d•$180,000 - $240,000•Onsite

About The Position

You’ll write and ship full-stack features end to end, from the agent runtime and backend APIs, to the web and desktop UI that users interact with every day. We're still ~15 people and shipping to our first paying users. You won't just be building features, you'll be making the decisions that determine whether this system holds at 1000x the current load. You'll work directly with our CTO. Here are a few examples of the kinds of things you might work on: Build and operate the sandbox infrastructure where agents execute code, process isolation, resource limits, secure credential handling across thousands of concurrent sessions. Design the deployment and migration pipeline for a Cloudflare Workers + Fly.io architecture, including blue-green rollouts and canary patterns. Instrument real-time workloads end to end: SSE streaming, task queues, and multi-model LLM provider routing. Ship new backend capabilities, tool integrations, scheduled task execution, memory indexing, and see them used by real people the same week. Reduce operational toil for a small team: structured logging, tracing, monitoring, and incident response tooling that actually works at our scale. $your ideas}.

Requirements

You have 5+ years of engineering experience building and operating backend systems in production.
You've been on-call.
You're fluent in TypeScript and comfortable working across the stack, but your instinct is to go deeper on the backend.
You've built real-time systems: WebSockets, SSE, event streaming, or message queues in production.
You have distributed systems intuition, you understand consistency tradeoffs and have opinions about them.
You've shipped infrastructure to real users, not just internal tooling.

Nice To Haves

You've worked with Cloudflare Workers, Durable Objects, or serverless compute at the edge.
You've built agent systems, model routing layers, or tool-use architectures with LLMs.
You've been a founder or early-stage engineer and care deeply about product.

Responsibilities

Write and ship full-stack features end to end
Build and operate the sandbox infrastructure where agents execute code, process isolation, resource limits, secure credential handling across thousands of concurrent sessions.
Design the deployment and migration pipeline for a Cloudflare Workers + Fly.io architecture, including blue-green rollouts and canary patterns.
Instrument real-time workloads end to end: SSE streaming, task queues, and multi-model LLM provider routing.
Ship new backend capabilities, tool integrations, scheduled task execution, memory indexing
Reduce operational toil for a small team: structured logging, tracing, monitoring, and incident response tooling