Principal Frontend Engineer (Full Stack)

Harnham; San Francisco (CA); Hybrid; USD 250,000 - 350,000; Full time

Job summary

Harnham is seeking a Principal Full Stack Engineer (Frontend) to lead the development of AI-powered product experiences in a hybrid Bay Area setting. You will own features from concept to launch, shaping scalable frontend and backend services and collaborating with cross-functional teams.

The role emphasizes building high-performance React/TypeScript interfaces, developing Python APIs, and delivering AI-powered capabilities such as intelligent search and recommendations.

Qualifications

• Proven frontend experience with React/TypeScript in production.
• Backend API development with Python and cloud-native architectures.
• Experience integrating AI/LLM capabilities into products.

Responsibilities

• Build polished, high-performance product experiences using React, TypeScript, and modern frontend technologies.
• Develop backend APIs and services using Python, cloud-native architectures, and modern data platforms.
• Create AI-powered features including intelligent search, recommendations, summarization, and conversational experiences.
• Partner closely with Product and Design to transform complex workflows into intuitive user experiences.
• Own features end-to-end, from architecture and implementation through launch and iteration.

Skills

React

TypeScript

Python

AWS / Cloud

LLMs integration

Product-minded

Ownership

Tools

AWS

Python APIs

Job description

PRINCIPAL FULL STACK ENGINEER (FRONT END)

$250K-$350K (Includes Base & Bonus) + Equity

Hybrid - Bay Area (3 Days/Week)

The Opportunity

Join a product-focused technology company building AI-powered experiences for a large and engaged professional audience. This is a hands-on leadership role for engineers who enjoy owning products from concept to launch.

What You'll Do

• Build polished, high-performance product experiences using React, TypeScript, and modern frontend technologies
• Develop backend APIs and services using Python, cloud-native architectures, and modern data platforms
• Create AI-powered features including intelligent search, recommendations, summarization, and conversational experiences
• Partner closely with Product and Design to transform complex workflows into intuitive user experiences
• Own features end-to-end, from architecture and implementation through launch and iteration

What They're Looking For

• Solid Python backend experience building production APIs and services
• Experience integrating LLMs, AI capabilities, or intelligent workflows into customer-facing products
• Proven track record building scalable applications on AWS or similar cloud platformsProduct-minded engineer with strong ownership, user empathy, and a builder mentality

Why This Role

• Build AI-powered experiences used by thousands of professionals every day
• Influence product direction, engineering culture, and technical architecture
• Work directly with Product, Design, AI, and Engineering leadership
• Own meaningful customer-facing features from idea to impact
• Join a collaborative environment with significant autonomy and responsibility

If you love building beautiful products, shipping quickly, and using AI to create entirely new user experiences, this role offers the opportunity to have an outsized impact. You'll own features end-to-end while helping shape the future direction of a growing AI-powered platform.