Senior Software Engineer

About Fathom

Fathom is on a mission to eliminate the billions of dollars of administrative waste in US healthcare. We're starting with one of its most expensive, labor-intensive workflows: medical coding. Using AI, we automate the translation of clinical notes into the billing codes used for provider reimbursement—a process that costs US hospitals $15B+ annually, plus tens of billions more in errors and denied claims.

The result is healthcare that spends less time and money on administration and more on what actually matters: patients. KLAS named us the #1 emerging technology for reducing the cost of care, and many of the nation's largest health systems, health plans, and physician groups rely on us to do it.

We're a Series B company backed by Lightspeed, Founders Fund, and CVS Health—taking on hard problems at the frontier of AI and healthcare, where getting it right has real consequences. We're scaling fast and looking for exceptional people who want their work to matter.

About the role

We are hiring a Senior Software Engineer to build the products and infrastructure at the core of that system. This is an agentic engineering role. You will direct fleets of coding agents—Claude Code and Codex—and orchestrate them to amplify your output. Your job is to architect, direct, review, and ship at a scale no individual coder reaches alone.

We operate agent-first. The mandate extends beyond automating output generation for our customer base. We are driving toward full automation of customer onboarding as well—turning what is today human-intensive integration and ramp work into agent-executed pipelines.

Hybrid only with 3 days in office weekly. New York City (Manhattan Financial District), Oakland, or Austin.

What you’ll do

• Orchestrate agent fleets to design, build, and ship data infrastructure that ingests, sanitizes, and normalizes a broad range of medical data—electronic health records, journals, established medical ontologies, crowd-sourced labeling, and other human inputs.

• Build infrastructure that scales both data ingest and large-scale cloud-based machine learning.

• Build performant, expressive interfaces to that data.

• Drive automation of customer onboarding—replace manual integration and ramp work with agent-executed systems.

• Operate as a force multiplier: set technical direction, direct humans and agents toward outcomes, and own delivery.

You may be a good fit if you have

• 5+ years of software engineering experience in a production setting.

• Demonstrated leverage from coding agents—you orchestrate them to multiply throughput rather than treating them as autocomplete.

• Strong command of algorithms, data structures, and systems design.

• Experience building data pipelines from disparate sources.

• Hands-on experience building and scaling compute clusters.

• Solid understanding of databases and large-scale data processing frameworks such as Hadoop or Spark, plus judgment on which tools fit which job.

• The creative and analytic range to design a system that pulls together, trains, and tests dozens of data sources under a unified ontology.

• A desire to collaborate in office 3 days weekly.

Bonus points if you have

• Experience building or supporting machine learning systems, including NLP toolkits like Stanford CoreNLP, OpenNLP, or Python's NLTK.

• Expertise wrangling healthcare data and/or HIPAA.

• Experience managing large-scale data labeling and acquisition through tools such as Amazon Mechanical Turk or DeepDive.

What we offer

• Salary: $150,000 USD - $230,000 USD (geo-dependent)

• Company Equity

• PTO and Uncapped Sick Days

• Medical/Dental/Vision Coverage

• 401k Matching

• $1,500 USD Home Office Budget