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).

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), 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.