# Simon Wonjoo Kim > Staff Software Engineer at Cepheid Location: San Jose, California, United States Profile: https://flows.cv/simonwonjookim With over a decade of experience, bring a proven track record in applications, web services, and security, excelling in leadership, collaboration, and efficient communication. Expertise lies in designing and developing diverse solutions that align with business objectives. Skilled in scalable microservice architectures and modern web applications within cloud environments. I possess deep knowledge and experience in PKI-based security services and access control. Also, analytical skills enable me to pinpoint issues and implement continuous process enhancements, and reduce costs through driving efficiency improvements. I am seeking a dynamic and innovative company where I can contribute to the design and implementation of service system architectures while delivering scalable solutions for large-scale services. [ Tech Stacks ] • Languages: Java, JavaScript, C/C++, SQL, Bash • Technologies: Spring Boot, J2EE, ORM/Hibernate/JPA, Docker, Swarm, Kubernetes, Helm, RabbitMQ, Kafka, Redis, Angular, NodeJS, MySQL, Oracle, MongoDB, XML, JSON, JUnit, Jenkins, Git, AWS, LDAP • Concept/Standards: OOP/OOD, TDD, REST, MSA, PKI(x.509), PKCS, RFCs, Crypto Algorithm, Agile • Network: TCP/IP, HTTP/S, Telnet/SSH etc. ## Work Experience ### Staff Software Engineer @ Cepheid Jan 2022 – Present | Sunnyvale, California, United States - Designing and implementing new features and functional enhancements on the Cepheid OS team for the Touchscreen & R3 system. Stacks: Java 11/17/21, Spring Boot, Angular, C++, MS-SQL, REST API, TLS, PKI, Codesign, LDAP, Vibe Coding etc. - Solved various mission-critical challenging problems, improved and expanded the system's stability and usability. ### Senior Software Engineer @ Cepheid Jan 2020 – Jan 2022 | Sunnyvale, California, United States Working as a full-stack senior software engineer. • Upgrading GeneXpert Xpress molecular analysis software to next-generation software on the Nexsys project team. Stacks: Java 8, Spring, Angular, C++, MS-SQL, REST API, XML etc. • Contribute to implementing new features, improving service performance, user interface, and code review. • Co-working with software engineer and quality assurance testing engineer. ### Consultant / Senior Software Engineer @ Visa Jan 2018 – Jan 2020 | Foster City, California • Worked as a contractor at Payment Team of MAP-PD. RS Software is the contract company. • Performed successfully improve functionality, performance, code quality, and a bug fix for 20+ payment gateway and common services. Stacks: Java 8, Vert.X, Spring, Redis, Hazelcast, ZeroMQ, Kafka, Oracle, REST API, XML, Vault, Consul etc. • Contributed to decompose 10+ payment gateway codes and containerize it to support micro-service and successfully deployed to production – Docker swarm - and Kubernetes environment. • Mentored Junior/Senior Software Engineer and collaborated with other teams on Austin and India. ### Senior Software Engineer @ DSMentoring Co., Ltd. Jan 2011 – Jan 2017 • Contributed to implement 8+ large and small solutions for personal, enterprise and government agencies. • Led full project to design and implement a mobile service that provides price information of crypto-currencies. Stacks: Java 8, Spring Boot, Angular, Ionic, Jenkins, Docker, and AWS-S3/EC2/CloudFront/RDS/MQ. • Redesigned and launched a log management and monitoring product for the directory server. Stacks: Java 8, Spring Boot, MongoDB, Redis, RabbitMQ, MariaDB, AngularJS, and LDAP. • Participated in implement an LDAP-to-various storage data synchronization system. Stacks: Spring framework, AngularJS, NodeJS (REST Proxy), MongoDB. • Designed user access control solutions and identity management solutions; implemented proxy server for user access control, protocol layer module, data en/decrypt module, data synchronization module, and web service. • Participated in design and implement PKI-based key escrow system (Key Management Infrastructure - KMI) project. Received an award from the Korean Prime Minister. Stacks: Unix C/C++, Visual C++ • Designed and implemented TCP/IP packet monitor/controller system and web-based client service for management. Stacks: Unix C/C++, Spring, Servlet, Applet, REST, JSON. • Performed improvement of performance, stability, and reliability and strengthen security issues by refactoring logic of various products. ## Education ### Master of Science (MS) in Bioinformatics Kongju National University ### Bachelor of Science (BS) in Computer Engineering Hansei University ## Contact & Social - LinkedIn: https://linkedin.com/in/simon-wonjoo-kim-01578832 --- Source: https://flows.cv/simonwonjookim JSON Resume: https://flows.cv/simonwonjookim/resume.json Last updated: 2026-04-12