Supported new functionality and resolved issues related to HSM, cryptographic APIs, the authorizationand issuance of bank cards. I contributed to the enhancement and maintenance of the cryptographicservice built on Spring Boot, implementing new features to improve its performance and reliability.Accomplishments:- Developed a Spring Boot service providing a cryptographic API using GOST encryption algorithmsfor the Faster Payments System (SBP) and SBPay.- Integrated our application with various payment HSMs and provided partial support for theirconfiguration, including bug fixes and new feature maintenance.- Resolved bugs related to card authorization and the processing and execution of issuer scripts.- Migrated from Oracle to PostgreSQL, rewriting stored procedures and creating tests to verify theirfunctionality.- Developed functionality for protecting sensitive data using AES encryption and TR-31implementation.- Maintained a cloud-based card printer that operated via a JSON API.