Software Engineer II, Corporate Tax & Compliance

Onshore•New York, NY

1d•Onsite

About The Position

Onshore is seeking a Software Engineer II for the Corporate Tax & Compliance team. This role involves building the infrastructure for tax filings, including amended returns and full corporate returns. The core of the work involves a versioned calculation graph, handling tax laws, structured extraction of returns, and integrating with IRS e-file infrastructure. The team operates in two lanes: filing infrastructure, and extraction and amendments, with a public deadline adding to the challenge and excitement.

Requirements

2+ years designing, shipping, and operating production software, from requirements through architecture, delivery, and post-launch iteration.
Strong proficiency in a typed language, in SQL, and in data modeling. We work in TypeScript; deep experience elsewhere with real interest in switching counts.
You've built correctness-critical software, or you can show us you think in invariants: systems where wrong output is an incident, not a bug.
An appetite for spec-heavy work. E-file schemas and the Internal Revenue Code reward the engineer who actually reads them.
Clear, precise communication on technical topics, in writing and in person.
Able to work in person at our New York City office.

Nice To Haves

Experience in tax, accounting, fintech, or payments infrastructure.
Experience building rules engines, calculation graphs, query engines, or anything compiler-shaped.
Experience with XML schema pipelines or government integration work (IRS MeF, EDGAR, state filing systems).
Experience with document extraction using LLMs where the tolerance for error was near zero.

Responsibilities

Build the versioned calculation graph: tax computation as data, with full lineage from source document to filed number
Ship e-file infrastructure: schema validation, transmission, acknowledgment handling, and the rejection remediation loop
Build structured extraction of as-filed returns accurate enough to amend against, and the workpapers that flag missed credits
Implement temporal law resolution: given a tax year and a fact pattern, apply the law as it stood, with citations that verify
Design the preparer workflow: review and sign-off roles, diagnostics, and an audit trail
Write the evals for what you ship; this team has a hard deadline and no tolerance for silent regressions