Historical snapshotsenior (5+ yrs)Captured Oct 5, 2026, 11:03 a.m.

CTO / Lead Engineer, Thirdbase Capital

Thirdbase

Location
San Francisco, CA, United States · Remote
Compensation
Not stated in this snapshot
Employment
Full-time
Experience level
SENIOR (5+ years exp)
Specialization
Software Engineer, Wellfound
Source
Wellfound

About Thirdbase Capital

Thirdbase Capital is a growth-stage venture platform investing in AI, defense, frontier tech, robotics, energy, and fintech. Our portfolio includes some of the most sought-after private companies in AI and deep tech. We are now building the internal technology that will define how we source and underwrite the next decade of investments.

The Role

  • We are hiring a founding engineer to build Thirdbase Intelligence, a proprietary system that helps us identify exceptional growth companies earlier than conventional investors.
  • The system will measure where top talent is moving, how product and AI usage is accelerating, and whether that activity is converting into durable revenue. The north-star question it must answer: "What private company is becoming dramatically better, faster than the market realizes, and what objective evidence proves it?"
  • This is a data-engineering-first mandate. You will begin with the longitudinal data model, entity resolution, ingestion pipelines, and scoring methodology, and add a natural-language interface once the data foundation is solid. The full technical scope will be shared with shortlisted candidates.

What You'll Work On

  • Designing a longitudinal data model that tracks companies, people, roles, and career transitions over time
  • Building reliable ingestion pipelines for licensed workforce, hiring, web, and developer-activity datasets
  • Entity resolution across messy real-world data at the scale of millions of companies and profiles
  • Quantitative scoring and ranking methodologies, with backtesting against historical investment outcomes
  • A secure, read-only connector framework for structured diligence on companies raising capital
  • An evidence-grounded query and alerting layer on top of the data platform, built with modern LLM tooling

What We're Looking For

  • 5+ years building data-intensive systems: pipelines, entity resolution, time-series infrastructure, and graph data models at scale
  • Strong backend engineering (Python and/or a systems language; SQL; modern orchestration and warehouse tooling)
  • Experience integrating third-party data APIs and building monitored, production-grade ingestion for imperfect datasets
  • Practical experience with LLM application development, including retrieval, structured outputs, and agentic workflows
  • Ability to design scoring and ranking methodologies and validate them empirically
  • A security-conscious mindset for handling sensitive third-party data under strict access controls and licensing terms
  • Self-direction, with the ability to own architecture end-to-end and work directly with the investment team

Nice to Have

  • Prior work on people or workforce data, alternative data for investing, or data platforms at growth or hedge funds
  • Experience building secure customer-facing data connectors (OAuth, read-only scopes, audit logging)
  • Background in quantitative research, recommender systems, or anomaly detection
  • Why This Role
  • You will own a greenfield build with direct impact on real investment decisions, work closely with the fund's partners, and create a system that compounds in value with every week of data collected. This is a chance to build the kind of proprietary infrastructure most funds only talk about.

How to Apply

Send your CV or portfolio along with brief answers to the following to [email protected]:

  • Describe the most complex data system you have built: its architecture, scale, and the hardest problem you solved.
  • If you had to merge person-level records from three overlapping datasets with inconsistent identifiers, how would you approach entity resolution and measure its accuracy?