Sr Software Engineer II

Pax8

5d•$170,000 - $185,000•Remote

About The Position

Software Engineer II (Remote, USA) to help build the next generation of Pax8’s financial infrastructure — a greenfield, mission‑critical platform where correctness, auditability, and scalability are non‑negotiable. This role sits within a newly formed FinTech Product & Engineering organization, charged with building Pax8’s core financial engine from the ground up. This is true 0→1 work, not a refactor. You’ll help design and deliver the systems that safely move, track, and reconcile money across the Pax8 ecosystem — while working in an environment that is AI‑forward by design, where modern tooling accelerates real delivery.

Requirements

Proven experience building financial or money‑handling systems such as billing, payments, ledgers, or transaction platforms where correctness and auditability are critical.
Strong understanding of financial integrity, compliance expectations, and failure modes — even outside traditional banking environments.
Substantial backend engineering expertise with Kotlin and Spring Boot, building production‑grade services.
Demonstrated experience with event‑driven architectures and tools such as Kafka, especially for financial workflows.
Comfort designing systems using Domain‑Driven Design, clean domain boundaries, and explicit event models.
Ability to operate confidently in environments where errors have real consequences and quality cannot be compromised.
A practical, hands‑on approach to AI‑enabled development — using coding agents, spec‑driven workflows, and AI‑assisted testing as part of daily delivery.
The presence and maturity to operate at Senior Software Engineer II level immediately, contributing leadership while supporting internal mobility and team growth.
Must hold valid right to work in USA.

Responsibilities

Build net‑new financial systems — design and deliver Pax8’s core financial infrastructure with a focus on auditability, scalability, performance, and bullet‑proof money handling.
Own complex financial domains — model transactions, events, and ledgers with clear domain boundaries and strong guarantees of correctness.
Design event‑driven architectures — using Kafka and asynchronous patterns to support reliable, traceable financial flows.
Apply Domain‑Driven Design — shaping clean domains, event models, and system boundaries that will scale with the business.
Collaborate deeply — working closely with product, engineering, and adjacent teams to turn complex financial requirements into working systems.
Lead through example — contributing to design and code reviews, mentoring peers, and raising the engineering bar without formal people management.
Support production systems — participating in on‑call rotations for critical financial workflows where accuracy and calm execution matter most.
Deliver faster with AI — using coding agents and generative AI to accelerate implementation, testing, and documentation while maintaining full ownership of quality.