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I'm a Full Stack Software Engineer with deep expertise in Python, Go, and Node.js, focused on building scalable APIs, distributed systems, and cloud-native applications for finance and healthcare. I design secure, high-performance systems that scale to millions of users, and I enjoy collaborating with front-end teams to deliver end-to-end digital solutions. I thrive in cross-functional environments, applying AI/ML, streaming data, and modern cloud architectures to drive operational impact while maintaining robust security and regulatory compliance.…I'm a Full Stack Software Engineer with deep expertise in Python, Go, and Node.js, focused on building scalable APIs, distributed systems, and cloud-native applications for finance and healthcare. I design secure, high-performance systems that scale to millions of users, and I enjoy collaborating with front-end teams to deliver end-to-end digital solutions. I thrive in cross-functional environments, applying AI/ML, streaming data, and modern cloud architectures to drive operational impact while maintaining robust security and regulatory compliance.

David Kapitan

Full Stack Developer, Back-End Developer, Web Developer, +2

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I'm a Full Stack Software Engineer with deep expertise in Python, Go, and Node.js, focused on building scalable APIs, distributed systems, and cloud-native applications for finance and healthcare. I design secure, high-performance systems that scale to millions of users, and I enjoy collaborating with front-end teams to deliver end-to-end digital solutions. I thrive in cross-functional environments, applying AI/ML, streaming data, and modern cloud architectures to drive operational impact while maintaining robust security and regulatory compliance.…I'm a Full Stack Software Engineer with deep expertise in Python, Go, and Node.js, focused on building scalable APIs, distributed systems, and cloud-native applications for finance and healthcare. I design secure, high-performance systems that scale to millions of users, and I enjoy collaborating with front-end teams to deliver end-to-end digital solutions. I thrive in cross-functional environments, applying AI/ML, streaming data, and modern cloud architectures to drive operational impact while maintaining robust security and regulatory compliance.

Available to hire

I’m a Full Stack Software Engineer with deep expertise in Python, Go, and Node.js, focused on building scalable APIs, distributed systems, and cloud-native applications for finance and healthcare. I design secure, high-performance systems that scale to millions of users, and I enjoy collaborating with front-end teams to deliver end-to-end digital solutions.

I thrive in cross-functional environments, applying AI/ML, streaming data, and modern cloud architectures to drive operational impact while maintaining robust security and regulatory compliance.

Skills

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Expert

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Work Experience

Full Stack Engineer at Visa

February 1, 2023 - Present

Designed and implemented scalable microservices using Python and Golang to optimize low-latency, high-throughput payment processing; built anomaly detection models for fraud and logistics monitoring; engineered high-performance APIs (GraphQL, gRPC, REST); developed real-time data pipelines with Kafka, Pulsar, and Flink; migrated monoliths to serverless/containerized architectures on AWS/GCP; implemented vector search for dispute resolution; built AI forecasting for dispute trends; optimized relational and distributed databases; created internal tools and dashboards; integrated FIDO2/WebAuthn for passwordless authentication; deployed federated learning across banks; delivered AI-assisted dispute workflows and graph-based fraud detection.

Backend Developer at Bayer

April 1, 2019 - January 1, 2023

Developed cloud-native health care platforms (HCIS) using Python (Django, Flask) and Node.js for claims adjudication, interoperability (FHIR/HL7), and real-time eligibility verification; migrated legacy systems to AWS; built predictive analytics (Scikit-learn, XGBoost) for fraud detection and readmission risk; designed real-time ETL pipelines (NiFi, Airflow, Celery); created patient dashboards and secure authentication; automated claims adjudication workflows; integrated HL7/EDI standards; built streaming workflows for eligibility and real-time processing; delivered AI chatbots and regulatory reporting tools.

Full Stack Developer at SYTOSS

May 1, 2014 - March 1, 2018

Developed and maintained enterprise apps across finance, healthcare, and retail; built RESTful APIs (Django REST Framework, Express.js); designed ETL pipelines (SQLAlchemy, Airflow, Pandas); optimized PostgreSQL/MySQL/SQL Server databases; created interactive dashboards; automated backend workflows with Celery; designed multi-tenant SaaS platforms; implemented RBAC and authentication; integrated ERP/CRM/financial systems; produced real-time analytics and documentation; contributed to cloud migration and NoSQL data modeling.