John Stevenson
John Stevenson

John Stevenson

Building agentic systems that run in production.
Raising agentic humans that run around my house.

Atlanta · ML Engineer · Co-founder+CTO, Juniper Labs (acquired) · Former teacher

Experience

What's happened so far...

  1. 012010–11

    Teach For America

    Denver Public Schools · Denver, CO

    Middle school math + science teacher

    Teaching math and science at a Title I middle school. Thirteen-year-olds: toughest technical audience I've ever had.

    99%of students on free or reduced lunch
  2. 022011–16

    Pinnacol Assurance

    Commercial workers' comp carrier · Denver, CO

    1. Customer service rep
    2. Underwriter
    3. BI analyst
    4. Data engineer

    My teaching skills were _soo_ great, that after I year I crash landed into an insurance company answering phones. Over five years I worked my way up through underwriting and analytics into engineering, and ended up building the data pipelines for price forecasting for the whole company.

    $600M+book of business priced
  3. 032016–19

    Cake Insure

    High-growth insurtech startup

    1. First employee
    2. Data scientist
    3. Director of data science

    Founding employee. I built the NLP models that let quoting run on its own, then built the team behind pricing, NLP, audit forecasting and automation.

    >93%of quotes automated by NLP
  4. 042019–20

    Juniper Labs

    ML-powered commercial insurance SaaS · Denver, CO

    Co-founder & CTO

    Co-founded a B2B data and ML company. We curated a billion-row business dataset with ML, ran it all on infrastructure I built in GCP, and sold the company in 2020.

    1B+rows curated with ML · acquired 2020
  5. 052020–25

    NEXT Insurance

    AI-powered digital insurer · Atlanta, GA

    1. Lead ML engineer, dataLabs
    2. ML engineering manager
    3. Head of AI engineering

    Five years, three jobs. I went from building greenfield lead scoring models to leading twelve engineers across ten time zones. We launched generative search for underwriting, a human-in-the-loop policy review platform, and more than twenty production inference services.

    3Btokens a month in production
  6. 062025–

    Ontra AI

    AI platform for private markets · Atlanta, GA

    1. Staff ML engineer
    2. Tech lead

    Now I serve as the ML tech lead behind Ontra's Insight product. Developed and productionalized agentic extraction of reams of messy legal documents. With that, build and maintain a graph of legal provisions for some of the largest Private Equity firms in the world. Millions of inference calls in production every month.

    0.74 → 0.93F1 on mission-critical extraction

Skills

What I bring

Leadership & product

  • 12+ years across AI, ML, backend, data and DevOps
  • Co-founder and CTO, two acquisitions
  • 5+ years leading global teams (12 reports, 10 time zones)
  • Working with product, engineering and the C-suite

ML engineering & infra

  • Python, FastAPI, Django, Celery
  • OpenAI Agents SDK, LiteLLM, Arize, vLLM
  • Kubernetes, Docker, Helm, Knative, Kong
  • PostgreSQL, Redis, Elasticsearch, SQS/SNS
  • Terraform, GitLab/GitHub CI, Prefect, Airflow
  • AWS, GCP, Azure

Domains

  • Agentic document extraction (long context)
  • Risk modeling and underwriting
  • Generative AI at scale (3B+ tokens/month)
  • Marketing attribution and churn prediction

How I work

The rules I try to live by

Lead from the front
I won't ask a team to do something I haven't done or won't do beside them.
See for yourself
Go to the factory floor. Sit with the user. Don't take anyone else's word for it.
Move toward the customer
The closer the work is to the person it serves, the less it needs to be argued about.
Stewardship before skills
Take care of the people and the systems you inherit. Skills can be taught.
Fortitudine vincimus
By endurance, we conquer.

Also: Eagle Scout, Navy kid, UNC Chapel Hill (economics and Spanish).

Lately

Notes from the work

Writing

Essays on building AI systems and teams.

Recipes

Small, copy-pasteable solutions I keep reaching for.