AI Agent Engineer (Coding Agent)

Sekai; San Francisco, Northern (CA, KY); Hybrid; USD 180,000 - 250,000; Full time

Benefits offered by this job

Competitive compensation: salary +equ

Full medical / health insurance

Job summary

Sekai is building the TikTok for mini apps—a fast-paced, AI-native consumer platform. We seek engineers who will own the end-to-end design of agent-driven app generation, focusing on systems-level thinking and reliable production deployment.

Responsibilities include building the agent harness layer, developing eval loops and testing, and designing model strategy for cost and latency. Remote-first, with ambitious, hands-on builders encouraged to apply.

Qualifications

• Experience building agentic systems with tool use, orchestration, retries and context management.
• Strong understanding of distributed / real-time systems.
• Research-and-ship mindset with production readiness in Python and/or TypeScript.
• Track record of shipping and operating production systems.
• Translate user goals into system-design decisions.

Responsibilities

• Designing and owning our agent harness layer and long-horizon workflows.
• Developing robust evaluation loops, including eval harnesses and testing.
• Designing model strategy for routing, benchmarking, reliability, cost and latency.

Skills

Agentic systems

Python

TypeScript

Distributed systems

Production systems

Product instincts

Education

Bachelor's degree in CS or related field

Tools

LangGraph

PydanticAI

Google ADK

Pi-mono

Vercel AI SDK

Job description

Sekai is building the TikTok for mini apps — an AI-driven consumer platform where people create, remix, share, and play interactive content instantly.

We are a Series A company backed by Khosla, a16z, Mayfield, and A*, with $30M raised to date. We are remote-first across all positions and are looking for ambitious, AI-native builders who want to help shape the next generation of consumer social products.

Here are Sekai’s download links:

• Android: https://play.google.com/store/apps/details?id=chat.sekai.app&hl=en_US

• IOS: https://apps.apple.com/us/app/sekai-create-remix-play/id6504506653

Why we're hiring

We're doubling down on creation quality and reliability. This is a key role with real ownership: you'll run the lane end-to-end and set the technical bar for agent-driven app generation. We want people who think in systems, not solutions. How do we generate fully autonomous software for recreational use? How do we generate it fast? And how do we do it tastefully? This role lives at the bleeding edge of what current AI can do — if those questions excite you, it's for you.

You will own

• Designing and owning our agent harness layer Building long-horizon agentic workflows with maximal autonomy

• Developing robust evaluation and quality loops, including eval harnesses, regression testing, and failure taxonomies

• Designing model strategy: routing, benchmarking, reliability, and cost/latency optimization Creating debuggable agent systems with tracing, metrics, alerts, and observability Researching novel approaches and shipping them to production

We're looking for

• You've built agentic systems — tool use, orchestration, retry/repair loops, context management — whether on raw provider APIs or frameworks like LangGraph, PydanticAI, Google ADK, Pi-mono, or Vercel AI SDK.

• You understand the tradeoffs well enough to know when the framework gets in your way. Experience with distributed / real-time systems

• A research-and-ship mindset: you treat open-ended problems as experiments, and you care as much about getting the result into production as discovering it Strong software engineering fundamentals, with depth in Python and/or TypeScript

• A track record of shipping and operating production systems A history of owning hard problems end to end — you can point to systems you built and the outcomes they drove, not just the tech you touched

• Strong product instincts: you can translate user-experience goals into system-design decisions

Bonus points

• Took a customer-facing product from 0 to 1

• Built a coding agent, devtool, IDE assistant, or code-generation pipeline (directly relevant — this is what we do)

• Built evaluation frameworks (automated scoring, regression suites, release gating)
  Designed MCP-style tool protocols or robust tool interfaces for LLM systems

• Experience training and/or fine-tuning LLMs

Compensation & benefits

• Competitive compensation: salary + equity

• Full medical / health insurance coverage health insurance

If you are excited about building at the frontier of AI, consumer social, and interactive entertainment, we would love to hear from you.

At Sekai, you will work with an AI-native team, move fast, own meaningful problems, and have the flexibility to explore new ideas from an early stage.