Mustafa Han

Modernized legacy banking systems by migrating IBM Mainframe business logic to a .NET 8 microservices architecture. Led DB migration from IBM DB2 to Microsoft SQL Server and used Entity Framework Core to build scalable data access layers while refactoring COBOL monoliths to reduce technical debt.

Optimized microservice performance by resolving bottlenecks and reducing execution time by 40%. Integrated Apache Kafka for event-driven data flow, improved Elasticsearch query performance, and reduced downtime by 10% using monitoring and proactive issue resolution.

Developed scalable applications using AWS serverless services, including Lambda, to reduce operational costs while improving scalability. Implemented EC2 autoscaling and migrated legacy data workloads to AWS RDS, using Terraform to standardize infrastructure as code.

Managed a backend team of 5 engineers and guided architectural decisions and solution direction across teams. Improved the development lifecycle by modernizing codebases, strengthening CI/CD and code review processes, and creating requirement traceability matrices to verify delivery consistency.

Migrated a .NET Framework monolith to distributed services using .NET Core and Go, enabling deployment on Kubernetes. Built Docker/Kubernetes deployment pipelines, improved reliability with caching (Redis/Varnish), and increased efficiency by 30% through load testing and performance tuning.

Developed and maintained RESTful API services in .NET Framework, including BFFs for mobile and website, and replaced Nancy services with .NET Core. Orchestrated new services with Kubernetes, implemented a MongoDB GeoJSON save-location feature, and migrated pipelines from GoCD to GitLab.

Built WCF and RESTful API services for online bill payments and integrated between banks and external institutions with different infrastructures. Developed asynchronous Windows Services for payment processing, automated production releases with TeamCity and Octopus, and performed database migrations using FluentMigrator with NHibernate as ORM.

Activities and societies: Member of Computer Science Club. Last year: worked at Sakarya University SABIS Team, developing and maintaining Student Management System; improved efficiency for over 80,000 students.

Bachelor of Science in Computer Engineering at Sakarya University (2011–2015). Member of the Computer Science Club and contributed to the university’s Student Management System for 80,000+ students.