Sr Software Engineer II

Pax8 is a fast-growing FinTech company focused on building a mission-critical financial infrastructure. The Sr Software Engineer II will design and deliver systems for financial transactions, ensuring correctness and scalability while collaborating with various teams.

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

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