With a comprehensive grasp of web development and automation, I'm confident that I can provide the perfect solution to fit your needs. My skills in backend, using languages like Node.js, Laravel, Python/Django, align perfectly with what's required for this project. I have built numerous tools and bots similar to what you're requesting, allowing me to expertly automate the login procedure while conserving the cookies for each account.
Moreover, given my experience in working with cloud services like AWS S3/Cognito/EC2/DynamoDB, GCP and proficiency in handling databases like MySQL, PostgreSQL, MongoDB; it’d be easier for me to overcome any infrastructure challenges we may face during this project. Adding to these concrete skills is my ability to effectively manage projects using popular tools such as Jira, Trello, Docker and having a strong version control knowledge with GitHub. On top of all that, there is an added advantage; I can proficiently consume Japanese API services with the help of my Japanese language proficiency on top of English.
Best regards