Software Engineer - Backend

The Opportunity
A family's estate plan structure rarely fits neatly into a schema. A trust may have been amended three times, an LLC might be held by two of the children through a different trust, and a beneficiary is often also a trustee. Provisions frequently depend on conditions that haven't happened yet.

Modeling that correctly is the first half of the job. The second is computing against it, which is where our tax engine comes in: estate and gift tax, generation-skipping transfers, strategies like GRATs and ILITs and QPRTs, and projections that ask what happens if a business grows sharply in value ten years from now and how that changes a family's charitable and family giving goals. As far as we know, it's the most complete implementation of the US transfer tax code in software anywhere.

You don't need to have worked on any of this before! None of us had. We're looking for someone who likes modeling complicated real-world systems accurately, and who wants to learn a deep domain from the JDs and CPAs on staff.

What you'll do
Own the modeling engine. Transfer tax computation, waterfall and distribution modeling, and the consolidation work that brings our calculations under one engine.
Model the domain flexibly and thoughtfully. Trusts and estates are complex and have a lot of moving parts. Data modeling is a really important part of this role.
Make correctness checkable. You'll work with our JDs and CPAs to validate against how practitioners compute things. We regularly talk to various state attorneys general to dig into the nitty-gritty of how specific interactions work in their tax code.
Support our agents. Extraction and agentic workflows are only as good as the data model they write into. We don't want agents doing any math, so we expose this deterministic layer (and the ability to do hypothetical modeling) via tools.
Who you are

Four or more years of software engineering experience, at companies with strong engineering practices. Beyond that:

You prefer domain complexity to infrastructure complexity. The hard part here is modeling an intricate real-world system correctly, not scaling a queue.
Rigorous about correctness. You think in edge cases, and you're uncomfortable shipping logic you can't verify.
Product-minded. You want to know why a calculation matters and who depends on it. You'll be shaping requirements, not receiving them.
Day to day tools

Our backend is Go, Postgres, Temporal, and GraphQL
Our monitoring is mostly in Honeycomb, Braintrust, and PostHog
You communicate well. With half the team remote, overcommunication is the name of the game!

Why you'll love working here

You'll be one of a small, senior team of engineers building a complex and high-value product. You'll get a lot of trust and responsibility early on.
You'll work closely with our CEO, Head of Engineering, and Head of Product.
You'll help build foundational product in a nascent category, with a lot of room to expand into large adjacent markets.
You'll ship constantly and hear fast feedback from customers.
We earnestly believe that Luminary represents a one-of-a-kind opportunity to have massive impact at profitable scale, and to have a ton of fun along the way.