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Summary

  • Name: Ayako Hayasaka, née Iwasaki
  • Job: Software engineer at LY Corporation in Tokyo, Japan
  • Role: Primarily responsible for providing company-wide technical support in web backend development.
  • Background: I have professional knowledge and experience in web backend development. Beyond my professional role, I am actively involved in building low-level systems such as container runtime or filesystem, as seen in my tech conference presentations.
  • Qualifications:
    • Medical Doctor License (2021)
    • IPA Security Specialist (2023)
    • IPA Database Specialist (2024)
    • TOEIC IP Score: 915 (2023)

Educational Background

DurationInstitutionMajor / DegreeNote
2023.4 - 2026.3Japan Advanced Institute of Science and TechnologyM.S. in Information ScienceTokyo satellite course for working professional students
2015.4 - 2021.3Kyoto University Faculty of MedicineB.S. in Medicine 

Work Experience

DurationCompanyPositionNote
2023.10 - PresentLY CorporationSoftware Engineer 
2023.4 - 2023.9Yahoo! JAPANSoftware EngineerCompany name change due to merger
2021.4 - 2023.3National Center for Global Health and MedicineResident doctor 
2020.5 - 2021.3[Part-time] RIKENResearcher 
2018.9 - 2021.3[Part-time] Quadlytics Inc.Researcher 
2018.3 - 2019.3[Part-time] CO-CONV, Corp.Corporate engineer 

Professional Experience

Software Engineer | SWAT Team, LY Corporation / Yahoo! JAPAN

A specialized task force dedicated to solving high-complexity and mission-critical technical challenges across the company.

  • Role & Core Tech Stack:
    • Provide wide-ranging technical support for high-priority, urgent projects with a focus on Web Backend development.
    • 3+ years of experience in Kotlin/Java and Spring Boot.
    • Full-stack coverage including Web Frontend (TypeScript + Next.js or React + Vite) and Infrastructure (Kubernetes manifest management, etc.).
  • Key Projects & Achievements:
    • Ark Developer QA Support (LLM-based QA support for the test design phase)
      • Served as Tech Lead, overseeing overall development including backend, frontend, and infrastructure setup for deployment.
    • SeekAI (Internal RAG-based productivity tool)
      • Developed the web application to enable RAG integration and managed Kubernetes manifests for stable deployment.
    • Yahoo! Chiebukuro “Minna no Chiebukuro” (LLM-powered Q&A feature)
      • Implemented the RAG-based answer generation engine, leveraging LLMs to extract and synthesize information from 160 million best answers.

Public Speaking & Publications

Conference Presentations

Official Blog Posts

Personal Projects

Kontainer Runtime Kotlin

  • A low layer container runtime built with Kotlin/Native
  • Presented this project at CloudNative Days Winter 2025 (link to slides)

Halycon Rust

  • Virtual filesystem for WebAssembly
  • Upcoming presentation at Open Source Summit 2026 (link to the session)

Contribution to OSS

Research Experience

Honors and Awards

  • JSAI Annual Conference Student Incentive Award (2019)

Publications

  • Hayasaka A: Design and Implementation of a Host-Independent File System for WebAssembly (Master Thesis) 2026
  • Iwasaki A, Fujiwara K, Nakayama C, et al. R-R interval-based sleep apnea screening by a recurrent neural network in a large clinical polysomnography dataset. Clinical Neurophysiology. 2022
  • Iwasaki A, Nakayama C, Fujiwara K, et al. Screening of sleep apnea based on heart rate variability and long short-term memory. Sleep Breath. 2021.
  • Okada D, Nakamura N, Wada T, Iwasaki A and Yamada R, Extension of Sinkhorn Method: Optimal Movement Estimation of Agents Moving at Constant Velocity, Transactions of the Japanese Society for Artificial Intelligence Vol.34 No.5 pp D-J13 1-7, 2019

Oral Presentations

  • Iwasaki A et al., Screening of Sleep Apnea Syndrome Based on Long Short-Term Memory and Heart Rate Variability, JSAI Annual Conference, 2019
  • Iwasaki A, Nakayama C, Fujiwara K, et al., Development of a Sleep Apnea Detection Algorithm Using Long Short-Term Memory and Heart Rate Variability, IEEE EMBC 2019, 2019
  • Iwasaki A, How to Apply AI Technology to Cardiovascular Practice, 84th Annual Scientific Session of the Japanese Circulation Society, 2020
  • Iwasaki A et al., A Case of Ankylosing Spondylitis Rediagnosed Due to Cervical Pain, 676th Kanto Regional Meeting of the Japanese Society of Internal Medicine

Poster Presentations

  • Iwasaki A, Nakayama C, Hori K, et al, Development and Validation of a Sleep Apnea Syndrome Screening Algorithm Using Heart Rate Variability and Long Short-Term Memory, European Sleep Research Society, 2020

Products Just For Fun

Low-level Programming

Custom Assembler & Compiler for the Jack Language Python Assembly

Networking

Home Network Monitoring with Grafana Python

  • Captured packets on the home network using a Raspberry Pi, identified destination web services from IP addresses, and visualized traffic in Grafana
  • Used a port-mirroring switch and wireless AP to ensure all packets reach the Raspberry Pi

Wi-Fi-based Clock-in System Python

  • Built to track overtime by recording when I arrive home, since there was no clock-in system at work
  • Detects whether my iPhone is connected to the home network via packet capture, and sends Slack notifications on departure/arrival

IoT

Automatic Blanket Puller Python

  • Built a machine using a Raspberry Pi and motor to pull off the blanket in winter mornings
  • The Raspberry Pi runs a web server allowing alarm time configuration from a smartphone

IoT-enforced Morning Bath Python

  • If the bathroom humidity doesn’t exceed a threshold by a set time each morning, the room lights start flashing endlessly
  • Controlled via Nature Remo and SwitchBot hygrometer through a Raspberry Pi

IoT-enforced Daily Weigh-in Python

  • If today’s weight hasn’t been measured by a set time, a cardiac arrest alarm sounds continuously
  • Weight data from Withings Body smart scale is fetched via API from a Raspberry Pi

Automation with Google Apps Script

Automated Household Accounting JavaScript

  • Built a system to scan receipts with a scanner, OCR them, and register entries in Zaim (a household accounting service)
  • OCR powered by Google Cloud Vision AI
  • Receipts with suspicious readings are corrected through an interactive system using the LINE Messaging API

Weather Forecast Bot JavaScript

  • A Twitter bot that tweets the Kyoto weather forecast at 6:30 AM every morning
  • Changes its icon based on the day’s forecast for at-a-glance weather info

Websites

SCP Network Wiki Python

Omocoro Channel Search Python ShellScript

  • A keyword search service for Omocoro Channel (a Japanese YouTube channel). Built with WordPress
  • Data fetched via YouTube Data API with fully automated new video ingestion. Build article here

Medical

Arterial Blood Gas Auto-interpreter JavaScript

  • A web form that interprets ABG results and suggests possible pathologies

Drug Information Manager JavaScript

  • A Google Spreadsheet that auto-fills drug classification and side effects when you enter a drug name

Lab Value Auto-formatter Visual Basic

  • A Word macro that automatically adds units and formats lab values copied from electronic medical records for clinical reports
  • Probably only compatible with IBM-based EMR systems

Others

Modified Pomodoro Technique JavaScript

  • A pomodoro timer with a break borrowing/debt system
  • Details here

YouTube Playlist Player JavaScript

  • A tool for shuffling / reverse-playing YouTube playlists
  • Details here

Birthday Celebration Shell Script C ShellScript

  • Expresses a friend’s Twitter icon and birthday message as mathematical formulas, then renders them with gnuplot

Private Account Follower Finder Python

  • Uses the Twitter API to scan accounts followed by my followees, searching for followers of private accounts I don’t follow

Amazon Prime Video Watch Party Chat Saver JavaScript

  • Scrapes the Watch Party chat window to download conversation history, since Amazon doesn’t save it

D-Card Transaction History Downloader Python

  • Logs into D-Card’s member page and scrapes transaction history

LINE Log Viewer Python

  • Reverse-engineers iOS backups stored on macOS to extract LINE conversation data and export as Markdown files
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