Python Developer(Payments)

Job DescriptionJPMorgan Chase is seeking a Principal Engineer for our Card Services Technology organization. You will own the application architecture of our card network platforms - designing, building, and evolving the Python-based services that power Chase's credit and debit card processing. You'll write production code, set engineering standards, and be accountable for the technical quality of software that processes billions of transactions annually.ResponsibilitiesArchitect and develop Python microservices and APIs integrating with Visa, Mastercard, and debit networks (Interlink, Pulse, NYCE, STAR)Own application design across core domains: authorization, clearing, settlement, dispute management, and fraudDefine data models, event schemas, and API contracts across card processing platformsLead architecture reviews and produce ADRs for new capabilities and modernization effortsBuild internal frameworks, libraries, and SDKs used across card technology teamsEstablish Python engineering standards - code structure, testing, CI/CD, observability, and API designDrive decomposition of legacy and mainframe-adjacent systems into clean service-oriented architecturesMentor staff and senior engineers on design patterns and software craftsmanshipRequired Qualifications10+ years of software engineering; 5+ years at principal-level or aboveExpert Python: FastAPI, asyncio, Pydantic, SQLAlchemy, pytestStrong application architecture background - microservices, event-driven design, DDD, clean/hexagonal architectureSolid understanding of card network processing: authorization flows, ISO 8583, clearing, settlement, chargebacksExperience building high-throughput, low-latency distributed systems in productionProficiency with Kafka or equivalent async messaging patternsStrong written and verbal communication; able to align technical and business stakeholdersPreferred QualificationsCard network certification experience (Visa, Mastercard, PIN debit)Familiarity with tokenization (EMVCo), 3-D Secure, or digital wallet integrationsCloud development on AWS, GCP, or Azure with Kubernetes/DockerBackground modernizing legacy payment platformsExperience authoring enterprise-level engineering RFCs or technical standardsTech StackPython FastAPI Pydantic SQLAlchemy Celery pytest Apache Kafka PostgreSQL Oracle Redis Kubernetes AWS Terraform GitHub Actions Splunk Dynatrace