Lead Software Engineer - Applied AI

Harnham; New York (NY); Remote; USD 315,000 - 385,000; Full time

Benefits offered by this job

Equity

Remote work on East Coast

Job summary

Harnham is seeking a Lead Software Engineer - Applied AI to be the CTO’s right hand and lead the development of a digital twin platform. You will architect and ship end-to-end LLM systems on GCP, collaborating with a lean team and reporting to the CTO.

The role requires 8+ years in software engineering with production LLM work, strong Python and cloud data experience, and excellent stakeholder communication. Equity is included and remote work on the East Coast is preferred.

Qualifications

• 8+ years in software engineering with production LLM work.
• Strong Python and cloud data experience.
• Experience building in scrappy startup environments.
• Clear communication with non-technical stakeholders.

Responsibilities

• Own the development of the digital twin platform from architecture to production.
• Stay hands-on, building LLM systems in Python with OpenAI/Anthropic/Gemini.
• Run on GCP (BigQuery, Cloud Run) with minimal DevOps support.
• Mentor and grow the engineers and analysts as the team scales.

Skills

Python

LLM development

Cloud data experience

Communication with stakeholders

Tools

OpenAI

Anthropic

Gemini

LangChain

LangGraph

Job description

Lead Software Engineer - Applid AI | Second in Command to the CTO

Remote, East Coast preferred | Up to $350k total comp + equity

The company

A profitable, fast-growing AI company spun out of a leading quant-backed investment firm, working with some of the largest private equity firms in the world (around $1T in combined assets). They build a digital twin of an organisation, simulating its people, processes and systems to show where AI can drive growth and efficiency.

AI for good

They don’t walk into a business and say cut 30% of your staff and replace them with AI. They use the digital twin to find opportunities for growth and efficiency, with AI working alongside people to improve what they already do. It’s a mission the whole team believes in, and they welcome healthy debate on AI, sceptics included.

The role

• Be the CTO’s right hand and technical number two
• Own the development of the digital twin platform, from architecture through to production
• Stay hands-on, building LLM systems in Python across OpenAI, Anthropic and Gemini (LangChain/LangGraph, RAG, agentic workflows, evals)
• Run on GCP (BigQuery, Cloud Run, CI/CD) with no big DevOps team behind you
• Support and mentor the engineers and analysts around you as the team scales

You’ll bring

• 8+ years in software engineering, with real production LLM work
• Strong Python and cloud data experience
• A builder’s mindset, ideally from a small, scrappy team or startup
• Clear communication with non-technical stakeholders
• Bonus: PE or finance exposure (easily learned on the job)

Why now

• Team has doubled in six months, with Series A expected shortly
• Greenfield build, so you choose the tools
• Early equity before the next round is priced
• A product used directly in engagements with top-tier PE clients

Process: screen, technical interview (take-home where AI tools are encouraged, followed by a walkthrough of your decisions), team conversations, then a final meeting with the founder.