Software Development Engineer at Amazon Web Services

Location: Seoul, Korea
Email: serithemage@gmail.com
Blog: moreagile.net
Linkedin: @serithemage

I have extensive experience as a Software Developer, Architect, Project Manager, IT Consultant, Tech Blogger, and Technical Trainer since 1995. I excel in software development tasks when provided with adequate resources, including time. My interests include soft skills, hard skills, team building, process optimization, programming languages, frameworks, and tooling related to software development optimization. I also like to talk about better software development with a wide range of people.

• Experienced in various cloud migration projects as a PM and architect at large Japanese companies such as All Nippon Airways (ANA), Nomura Research Institute (NRI), and Oryx.
• I have worked as a Technical Trainer at AWS for six years, interacting with numerous customers undergoing cloud migrations through classes and workshops. This experience has given me insight into the common mistakes customers make during cloud migrations and the ability to provide effective solutions to address or prevent them.
• I identified potential technical and schedule risks with the team during the planning phase of the cloud migration project and established a framework to monitor them regularly.

• In my personal IT consulting experience, the success of a project is determined by the management of customer expectations. We build trust with our clients by giving them realistic goals and sticking to them. This requires scope management and key personnel management.
• I have three and a half years of experience working as an IT consultant at Mamezou, the most famous local IT consulting firm in Japan. Korea and Japan share a lot of corporate culture, so I am confident that my experience as a consultant in Japan will be useful in Korea.
• In ANA's cloud migration project, he was initially involved in the design as an architect due to his excellent risk management skills, but during the implementation phase, he changed his role to PM at the request of the client and successfully completed the project.
• As an external consultant/PM, I would emphasize the importance of building trusting relationships with clients over the long term. As a PM, it's not just about making a single project successful, it's about making clients understand that both the company and the individual benefit from working with us. This requires being able to look closely at the needs of stakeholders, and I think this is as important a skill as risk management as a project manager in Korea or Japan.

• In 2013, I had the opportunity to learn about CI/CD directly from Jenkins creator Kohsuke Kawaguchi. Since then, I have been running a developer community and blog as a passionate advocate for DevOps/Agile processes.
• Recently, I introduced my team to an automated code review process using GenAI, which has helped us cut the time developers spend on code reviews by more than half.

• JavaScript ES6 & TypeScript 5
• Python3
• Java17

• AWS
  • Serverless Architecture
    • Lambda, StepFunction, API G/W, AppSync
  • DevOps
    • CodeCommit, CodeGuru, CodeBuild, CodeDeploy
  • MLOps
    • Sagemaker, Glue

• DynamoDB
• MySQL(RDS, Aurora)
• Redshift
• Neptune (Graph DB)
  • Neo4J

• Pandas
• Scikit-Learn

• React
• Svelte

• Git
• Docker
• ECS/Fargate
• Kubernetes
• GraphQL

• From July 2022 to September 2023, as Acting Manager, I ran the team building and operations of Amazon's first development team in Korea.
  • Prioritized work based on customer experience, identified team members' capabilities and desires, assigned responsibilities, and managed risk.
  • As of September 2023, a full-time manager has been hired and I have been focusing on the role of SDE.
• As a Senior Developer in AWS T&C Services Development, responsible for the development and operation of skillbuilder.aws, a service for AWS learning.
  • Designed and implemented a serverless architecture using DDD principles.
  • Improved front-end latency by 500% based on customer feedback.
• Developed an A/B testing service using TypeScript and AWS CDK, creating a fully automated CI/CD pipeline.

• Delivered training on a variety of AWS subjects including AWS Cloud Practitioner Essentials, AWS Technical Essentials, Architecting on AWS, and more.
• Taught courses primarily related to Security, Development, ML Pipeline and DevOps.
  • Architecting on AWS
  • Advanced Architecting on AWS
  • Security Engineering on AWS
  • Running Containers on Amazon Elastic Kubernetes Service (Amazon EKS)
  • Big Data on AWS
  • Developing on AWS
  • Advanced Developing on AWS
  • DevOps Engineering on AWS
  • Deep Learning on AWS
  • MLOps Engineering on AWS
  • Machine Learning Pipeline on AWS
  • Developing Serverless Solutions on AWS

• Improved development processes and managed cloud migration projects.
• Led multiple projects building DevOps pipelines centered on Jenkins/Git

• Orix Next Generation Leasing System Development Project (2015.1 ~ 2016. 5)
  • As PM, I led the introduction of Scrum processes and automated CI/CD pipelines.
  • Prior to my arrival, the project had been executed by another vendor and was drifting over budget and deadline.
  • Since the leasing business was a specialized domain, we conducted a business study with the client to help the team members understand the client's business in a short period of time.
    • I created a quiz after every class to check for comprehension of the lesson so that team members would be motivated to learn.
  • I suggested to the client to organize a team with a small number of elite people to reduce communication costs, and the project was successfully delivered on time. The project was named the most successful IT project at Orix that year and we received a plaque of appreciation from the client.
• ANA Cloud Migration Project (2013.11 ~ 2014.12)
  • Join the project as an architect for the first 3 months.
    • Our team built a CI/CD pipeline centered around Jenkins and trained developers on unit and integration testing with JUnit.
  • Spent the next 9 months as a PM designing/implementing a web ticketing service.
    • At the time, most developers were skeptical about writing unit tests. I built a team of young leaders who were willing to learn. I trained the developers on how to write unit tests and created a wiki to share the training with the rest of the team.
    • However, other teams refused to adopt unit tests and Jenkins CI/CD and insisted on traditional manual testing. As a result, our team completed the project on schedule and on time, while the other teams failed to pass acceptance tests and went over schedule and budget.

• During my time at this company, I have worked mostly as an SI developer and manager. In addition to working on projects as a developer, I was also responsible for hiring and training employees, especially by introducing coding tests into the hiring process, which was new at the time, to improve the quality of new hires.

• Developed enterprise and embedded applications.
• Standardized development processes and managed projects.

• I have been involved in ActiveX-based web game development projects as a developer and PM.
• I modernized the versioning of source code by taking over CVS, which was rarely used in Korea at the time.

• 배워서 바로 쓰는 14가지 AWS 구축패턴 (Amazon Web Services 定番業務システム14パターン 設計ガイド韓国語訳) - Hanbit Media, 2020
• 실전 AWS 워크북(Amazon WebServices 定番業務システム12パターン 設計ガイド 韓国語訳) - Hanbit Media, 2017
• 나는 프로그래머다 2탄 - Hanbit Media, 2016
• 나는 프로그래머다 - Hanbit Media, 2015

• QCon Tokyo 2015 executive committee member

• Producer & Host
• Developer meetup NapuCon organize

• A member of a community leader group
• Hands-on meetup organizer

• Bachelor of Science (BS), Mathematics(Major) and Computer Science(Minor)