Senior Full Stack Software Engineer

Cynch AI is a Series A company that has grown revenue 4x in the past year.

We build neuro‑symbolic AI applications for our accounting firm, Aardvark Tax Advisors, so our tax professionals can focus on the work and decisions that matter most. We are growing both organically and through strategic acquisitions, with a mix of remote and onsite employees and offices in San Francisco, the South Bay, and the East Bay.

We are looking for a senior software engineer who has fully embraced AI tooling

and wants to stay at the forefront of how modern engineering teams move faster, build higher‑quality software, and solve more ambitious problems. This is a full stack role with a backend bias: you’ll work across the stack, but the hardest problems are in the data model, execution engines, and reliability—not just the UI or API surface.

The kind of work you may own here includes building execution engines for AI‑assisted tax workflows, document‑processing pipelines, data models for complex domain logic, systems for tracing and auditing automated decisions, integrations with tax/accounting platforms, and internal platforms that allow a small operations team to handle substantially more customer volume. You do not need prior tax or accounting experience, but you should have experience building production software where correctness, performance, and reliability really mattered.

We are changing how software can be built as we are building it; being all‑in on AI‑assisted development is central to this role.

What You’ll Do* Work with founders, product, AI, operations and domain experts as you fully own substantial product and platform work from problem definition through production rollout. * Build backend systems that can handle real production complexity: clear APIs, well‑modeled data, reliable execution, useful observability, and maintainable code. * Turn messy operational workflows into clean software abstractions, internal tools, automations, and customer‑facing featu...