Principal Full Stack Engineer
HarnhamAbout the role
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
Strong expertise in React, TypeScript, JavaScript, and frontend architecture
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 platforms
Product-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.
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
Qualifications
- Strong expertise in React, TypeScript, JavaScript, and frontend architecture
- 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 platforms
- Product-minded engineer with strong ownership, user empathy, and a builder mentality
Benefits
- Equity
- Collaborative environment with significant autonomy and responsibility
Skills mentioned
About Harnham
Harnham provides specialist Data and AI recruitment and staffing services, along with bespoke training solutions, across multiple industry verticals, operating in the UK, the USA and EU - contact us today to discuss your requirements: info@harnham.com Our recruitment and talent teams cover all aspects of the data and AI pipeline, from collection to consumption, across multiple data roles and functions. Whether you need full-time staff, contract talent, specialized training, Data-qualified graduates, or C-suite executives, Harnham Group is equipped to fulfill all your data talent requirements. Our five core services: * ATD - Rockborne – our graduate development arm – deploys expertly trained data consultants, who have gone through an intensive 12-week data training programme. After two years in the scheme, your consultant could become a * Contract / C2C / Freelance: Whether you're addressing a talent shortage, augmenting a project team, or encountering resource gaps, our specialist consultants offer bespoke interim talent solutions to address your unique challenges and drive success. * Full-Time / Direct Hiring: From early career professionals to senior management, our comprehensive services enable you to unearth outstanding data talent across various specializations, ensuring your organization thrives in the data-driven era. * Executive Search: With our dedicated executive search team and an extensive network encompassing the director to C-suite level, we assist both global corporations and ambitious startups in securing top-tier leadership talent to accomplish their goals. * GenAI, Prompt, LLM Training: Elevate your team's data expertise with our all-encompassing training programs covering essential tools and technologies such as Python, SQL, Machine Learning, LLM’s and AI. Highly bespoke, customised to your team learning requirements and budgets.