Senior Frontend Engineer — Agentic AI UI Ownership

Sift Stack, Inc.; San Francisco (CA); On-site; USD 180,000 - 230,000; Full time

Job summary

Sift, based in Marina Del Rey, CA, is seeking a senior product engineer to own the Sift Agents frontend. You will talk directly to customers, decide what to build, and ship it from MVP onward, shaping dashboards, analysis scripts, and insights derived from telemetry.

You’ll craft high-performance web apps with React, NextJS, and TypeScript, pushing browser limits with Web Workers and advanced caching while ensuring the agent’s work is transparent and trusted by engineers.

Qualifications

• Experience building high-performance web applications using modern frontend tech.
• Proven ability to own product areas, talk to customers, decide what to build and ship.
• Comfort with React/NextJS/TypeScript and architectural decisions impacting UX and performance.
• Attention to detail in micro-interactions, latency, FPS, and polish of interfaces.
• Curiosity about AI products and willingness to evaluate new agents, models, and features.

Responsibilities

• Talk directly to customers and partner with product to translate review workflows into agent capabilities (dashboards, analysis scripts, insights).
• Build the frontend surfaces where Sift Agents live and ensure they feel great.
• Design interaction patterns for agentic UX (streaming responses, long tasks, interruptions, traceability).
• Render agent findings alongside telemetry and keep the UI fast with large datasets.
• Push browser performance with Web Workers, advanced caching, and selective framework optimizations.
• Contribute to a cohesive component library for consistent agentic UI across the product.
• Collaborate with backend and full-stack engineers on API design powering agent sessions.

Skills

Software engineering

Product ownership

Frontend development

AI product awareness

Customer interviewing

Tools

React

NextJS

TypeScript

Tailwind

WebAssembly

D3.js

WebGL

Go

Kafka

Flink

Redpanda

DuckDB

Timescale

QuestDB

InfluxDB

Druid

GitHub Actions

AWS

Azure

GCP

Docker

Kubernetes

Terraform

Job description

Sift, based in Marina Del Rey, CA, is seeking a senior product engineer to own the Sift Agents frontend. You will talk directly to customers, decide what to build, and ship it from MVP onward, shaping dashboards, analysis scripts, and insights derived from telemetry.

You’ll craft high-performance web apps with React, NextJS, and TypeScript, pushing browser limits with Web Workers and advanced caching while ensuring the agent’s work is transparent and trusted by engineers.