Senior Staff Software Engineer

Maximum is AI infrastructure for banks, delivering an operating system purpose-built for the next century of banking. By embedding intelligence natively at the foundation, Maximum empowers banks to automate complex operations, surface real-time insights, and drive growth with innovative financial products. The entire platform is engineered from the ground up to defend against modern, sophisticated threats protecting the bank and its customers.

About the Role

Maximum is building a core banking platform. Not a layer on top of a legacy core: the ledger, product, payments, card and compliance systems a bank actually runs on. As a Senior Staff Engineer, you would help to shape decisions, pressure-test them, and own the work that turns them into systems that hold. You would own the guarantees that have to hold everywhere, such as ledger invariants, auditability and consistency across domains, and lead the builds that cut across the whole platform. You would write a lot of code, much of it on the hardest path. We use AI coding agents heavily, and you would set the standard for how we use them as the team grows.

Responsibilities

• Own a domain service end to end: schema, gRPC API, workflows, event consumers, tests, and the docs that explain why you built it the way you did.

• Design tables and queries in our schema DSL.

• Write workflows that survive partial failure: replay-safe, idempotent, and resumable from the step that broke.

• Test against real environments in containers. Mocking is a last resort, and we will ask why you needed it.

• Review pull requests from humans and from agents, with the same suspicion for both.

• Turn messy external inputs into a data model that holds: a vendor file spec, a regulation, a feature or integration.

Qualifications

Must Have

• A long track record shipping backend systems in statically typed languages, including a system of record that others built on and that you lived with for years. Go preferred. Strong experience in Java, C#, Rust or TypeScript is also welcome.

• Expert-level data and SQL judgment: you have designed data models meant to outlast their first several products, and evolved them without losing correctness.

• You have led technical work that spanned a whole product or platform, beyond a single team’s scope, and can point to outcomes that came from it.

• Deep distributed systems experience: you can weigh consistency models for a platform, argue for one, and know what each costs.

• You disagree well. You can challenge a design with evidence, then commit fully once the call is made.

• You write production code every week and want to keep doing it.

• You can explain technical risk to founders, partners and regulators in terms they can act on.

• You have shaped how a team works with AI coding agents, and you have a view on where that practice should go next.

• Exceptional technical writing. At our size, your design docs are how the architecture survives the next ten hires.

Nice to Have

• Banking, payments, ledger, card or ACH experience helps, particularly building or running a core ledger

• Experience taking a system through a regulatory exam, audit or bank partner due diligence.

• You have been an early engineer at a startup and helped it through its first stretch of growth.