Sr Software Engineer II

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.

🚀 Why this role stands out

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.

🌈 Life at Pax8

Pax8 is where ambitious technology meets human‑centered culture. We’re fast‑growing, creatively offbeat, and serious about building software that matters. You’ll join a team that values curiosity, ownership, and craftsmanship — and where internal growth and fairness are taken seriously alongside high performance.
Learn more about our culture and mission on the https://www.pax8.com/careers/ and explore how we’re evolving our platform on the https://www.pax8.com/blog/.

🧩 What you’ll do

• 🏗 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.
   

You’ll help create the financial backbone of Pax8 — systems where mistakes are unacceptable, trust is paramount, and scale is built in from day one. Your work will directly support compliance, partner confidence, and Pax8’s ability to grow responsibly.
 

• 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.

At Pax8, we care deeply about building genuine, trust based relationships — starting with how we hire.

To protect our business, our teams, and our customers, we use a range of measures throughout the recruitment process to help confirm authenticity and prevent fraud. These safeguards are designed to be fair, respectful, and proportionate, and may evolve as risks change. By applying, you acknowledge that we take steps to verify identity and representation during hiring. If you're applying as your authentic self, you have nothing to worry about — we're excited to meet you.