Japanese tech companies hiring software developers.
18 Sep 2025
Success Story: Indonesian Full-Stack Engineer with AI/ML Background — ¥5,700,000 / year
Success Story: Indonesian Full-Stack Engineer with AI/ML Background — ¥5,700,000 / year
Hi, I’m Kotaro Muramoto, CEO of JOBs Japan. This is a success story that shows how strong AI/ML skills + full-stack proficiency + fast execution can get you an excellent role in Japan.
Candidate Snapshot
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Nationality: Indonesia
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Strengths:
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Experience building AI & machine learning systems for global companies (USA, Singapore, Indonesia)
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Full stack work: frontend + backend
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Particularly strong with Node.js (backend) & Vue.js (frontend)
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Able to prototype quickly, lead architecture decisions, and optimize systems end-to-end
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Key Achievements / Projects
Some examples of what made this candidate stand out:
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Optimized GraphQL queries to improve data fetch speed by ~50%
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Reduced CPU usage by ~70% using Puppeteer optimizations
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Worked with large language models (LLMs) to extract required information automatically from contract PDFs
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Led architecture redesign and migration to a monorepo setup to boost development efficiency
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Shortened deployment time (~20%) using CI/CD tools like GitHub Actions or GitLab CI/CD
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Improved database query time from ~60 seconds down to ~10 seconds, and built automated cleanup for unused AWS S3 data
The Hiring Process & Role
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The company is an innovation management firm: they help existing enterprises and startups turn ideas & technology into scalable businesses.
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The team uses LLMs / AI to analyze global startup data and help corporations & governments collaborate more effectively with overseas startups.
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Role required a tech-lead level engineer who can work both front and backend, build prototypes fast, and participate in both architecture and hands-on coding.
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The process moved very quickly: 8 candidates interviewed via Zoom over 2 weeks, feedback tracked via shared docs and spreadsheets. This candidate was selected 2 weeks after being introduced.
Why This Candidate Was Chosen
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Able to move fast & prototype — this reduces the time before you can start delivering value.
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Strong AI/ML + Full-Stack + Architecture combo — many people have one or two of those, but all three is a premium.
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Optimization & performance mindset — they didn’t just build features; they improved speed, reduced compute, optimized queries.
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Experience across geographies / global companies — helps in understanding scale, cross-cultural teams, diverse challenges.
What This Means for You (How to Learn / Apply It)
If you want similar success, consider:
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Build concrete AI / ML projects, especially ones using LLMs or data extraction / NLP / computer vision etc.
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Be proficient in both frontend and backend so you can contribute across the stack or switch as needed.
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Gather experience in optimization, profiling, query tuning, CI/CD, performance improvements. These are often what separate “good” from “outstanding”.
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If possible, show leadership: architecture decisions, migrations, improving development efficiency.
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Be ready to respond quickly in interviews. Having your resume ready, examples & stories prepared, and being responsive speeds up the process.
Outcome & Reflection
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Annual salary offered: ¥5,700,000
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Role: Full-Stack Engineer with responsibilities spanning front & back end, prototyping, architecture, performance, AI/ML components.