Software Engineer

SOFTWARE ENGINEER, AI AGENTS

ABOUT REACHER

We're the #1 TikTok Shop partner helping brands like Under Armour, Hanes, HeyDude, and Logitech scale their affiliate marketing. We've crossed 7 figures in ARR and are backed byY Combinator, Pioneer Fund, Rebel Fund, and operators including Steve Huffman (CEO of Reddit), Matteo Franceschetti (CEO of Eight Sleep), Theo Browne (t3.gg http://t3.gg).

We're making a big bet on AI agents and what they can do for creator marketing. This role sits at the center of that.

WHAT YOU'LL DO

AI Agents

• Build and own long-running AI agents that automate complex, multi-step workflows for TikTok Shop brands.
• Design agentic systems end-to-end: orchestration, state management, error recovery, and observability.

Backend & Infrastructure

• Own the backend systems your agents run on — design, implement, ship, maintain. Python, FastAPI, PostgreSQL, GCP.
• Contribute to our jobs infrastructure (GKE-based, on-demand workers) as needed to support agent reliability and scale.
• Set the bar for code quality and architecture decisions across the backend.

You're a Fit If

• 3+ years of backend engineering experience, ideally at a product-first company
• You've built automation, agents, or complex async systems — and you think deeply about failure modes
• Strong systems thinking, but applied toward agent reliability and workflow design, not just raw infra
• Comfortable with ambiguity and own problems end-to-end without hand-holding
• You've worked directly with customers or product teams and can translate vague requirements into technical decisions
• Resourceful: you figure things out, you don't wait for the answer to show up

Technical Skills We Value

AI and Agentic Development

• AI agent frameworks and LLM orchestration for building and managing long-running, multi-step agents
• Claude Code proficiency: context engineering (CLAUDE.md http://CLAUDE.md), custom commands, MCP integrations, subagent coordination
• Strong judgment for when to leverage AI vs. when to code directly
• Ability to decompose complex engineering work into tasks suitable for AI assistance
• Experience verifying AI-generated code for correctness, security, and maintainability

Backend

• Python, FastAPI, PostgreSQL
• System design with a focus on async, long-running, stateful workflows
• GCP/cloud infrastructure (GKE/KEDA) — enough to own what your agents need
• API design (REST/GraphQL)

General

• Testing frameworks (Playwright, Pytest) — especially for validating agent behavior end-to-end
• Code reviews, documentation, and establishing conventions

BONUS POINTS

• You've been an early engineering hire at a startup
• You've built or maintained internal automation systems that ran at scale
• You've worked on AI agents, LLM pipelines, or autonomous systems
• You've shipped side projects or contributed to open source
• You're curious about e-commerce, creator marketing, or what AI will do to the agency business

WHY JOIN

• Small team (5 engineers), high ownership — you're working on the hardest problems, not feature tickets
• You'll work closely with the founders in SF on the longest-term bets in the company
• Real equity, we care about it as much as salary

LOCATION

On-site in San Francisco. This role is meant to be close to the founding team.

WHEN APPLYING

Send a short note about something you've built and why this role excites you. GitHub, LinkedIn, resume all welcome, but I care more about how you think and what you've shipped.