fummicc1

—— 2026 / Software Engineer

FumiyaTanaka.

Software Engineer, connecting the dots.

iOSWebBackendMachine Learning
Get in touchProjects ↓
—— 01About

A bit
about me.

Hi, I'm Fumiya Tanaka (fummicc1) — a software engineer based in Yokohama, Japan, who builds products end-to-end across iOS, web, and backend.

I shipped my first iOS app at 17, and have since deepened my mobile craft while broadening across web, backend, and machine learning. I hold a Master's degree in Integrated Design Engineering from Keio University, where I researched dynamic adaptation methods for data drift in video analysis.

What I enjoy most is taking products from a rough idea to a polished, production-ready experience — at any layer of the stack.

—— 02Skills

What
I work
with.

Hover or tap each skill to see related products & experience.

/ Languages

SwiftTypeScriptDartGoPythonKotlin

/ Mobile

iOS App DevelopmentFlutterAndroid App Development

/ Web & Backend

Next.jsFirebaseCloudflare WorkersNestJSNode.js

/ Cloud & Infrastructure

Google CloudKubernetesPostgreSQLAWS
—— 03Career

Where
I’ve
been.

  1. 2026.4Present

    SaaS Company

    Software Engineer (Full-time)

    Building B2B web applications.

    GoNext.jsGoogle CloudKubernetes
  2. 2023.102024.2

    Recruit Co., Ltd.

    iOS Application Engineer (Contract)

    Developed a B2C language learning iOS app (2 days/week).

    SwiftSwiftUISwift ConcurrencyXcode
  3. 2023.42026.3

    Keio University Graduate School

    M.E., Integrated Design Engineering

    Research: Dynamic adaptation methods for data drift in video analysis.

  4. 2023.2Present

    EV Charging Startup

    Software Engineer (Contractor)

    Developing backend services and mobile apps for EV charging infrastructure.

    FlutterNestJSPostgreSQLGoogle CloudKubernetes
  5. 2023.12026.3

    System Development Company

    Application Engineer (Contractor)

    Application development across mobile and web for client projects.

    SwiftiOSFlutterDartNext.jsNode.jsAWS
  6. 2022.92022.12

    Mercari, Inc.

    iOS Application Engineer (Internship)

    Developed the iOS version of the C2C marketplace app.

    SwiftSwiftUIXcode
  7. 2018.62023.2

    Life is Tech, Inc.

    University Student Mentor

    Taught iOS and Android app development to middle and high school students.

  8. 2018.42023.3

    Keio University

    B.E., Electrical Information Engineering

    Research: Optimization methods for deep learning models in video analysis.

View full history on LinkedIn
—— 04Selected work

Things
I’ve
shipped.

/ Apps

  • ToiletMap icon

    ToiletMap

    A health-focused restroom diary and accessible restroom finder. Log urine volume/color and stool form to surface bodily patterns, and discover nearby accessible restrooms on a community-built map. Localized in Japanese, English, and Chinese.

    SwiftSwiftUIModular Swift PackagesFirebaseMapKitMulti-language (ja/en/zh)
    Website
  • PremierPulse icon

    PremierPulse

    A Premier League fan platform combining curated YouTube highlights, match data, and AI-generated articles. Built on Cloudflare Workers + D1 with multiple cron jobs handling video sync, football data, and trend analysis.

    TypeScriptNext.jsCloudflare WorkersD1 / Drizzle ORMYouTube APIAI Article Generation
    Website
  • Csv2Img icon

    Csv2Img

    A CSV to PNG/PDF converter, available as a SwiftUI app on iOS/macOS and as an open-source Swift Package.

    SwiftSwiftUIMultiplatform (iOS/macOS)Swift PackageCore GraphicsDocC
    GitHub
  • AltNega icon

    AltNega

    A mindfulness app that helps you reduce negative language. Log negative words and receive positive alternatives, with a daily dashboard, full history, Home Screen widget, and a watchOS companion.

    Swift 6.2SwiftUIwatchOSWidgetKitSwift PackageiOS 26+
  • Hashimoto icon

    Hashimoto

    A privacy-first app for managing thyroid health. Record medications, daily symptoms, and lab values, then export PDF/text reports for doctor visits — all data stays on your device.

    SwiftSwiftUIOn-device StoragePDF ExportLocal NotificationsPrivacy-focused Design
  • Decoder icon

    Decoder

    A radix conversion puzzle game built with Flutter. Solve puzzles by converting between binary, octal, decimal, and hexadecimal — featuring sound effects, haptics, and progressive difficulty.

    FlutterDartRiverpodFirebase AnalyticsIn-App PurchaseMobile Ads
  • se-masked-quiz icon

    se-masked-quiz

    A fill-in-the-blank quiz on swift-evolution proposals. A companion iOS app paired with a content management server built on Next.js, PayloadCMS, and Cloudflare Workers (D1, R2).

    SwiftSwiftUITypeScriptNext.jsPayloadCMSCloudflare D1 / R2
    GitHub
  • TabTidy icon

    TabTidy

    A Safari Web Extension for iOS and macOS that organizes, deduplicates, and groups your tabs to keep browsing focused. Native Safari distribution via App Store.

    TypeScriptSafari Web ExtensionManifest V3Jestesbuild
  • Viary icon

    Viary

    A voice diary application for iOS with sentiment analysis. Capture daily reflections by voice and visualize emotional patterns over time.

    SwiftSwiftUISpeech RecognitionSentiment Analysis (NLP)

/ Open Source

  • swift-complexity

    A code complexity analyzer for Swift. Calculates cyclomatic and cognitive complexity for Swift source files to surface refactoring candidates.

    SwiftSwift PackageStatic AnalysisAST Parsing
    GitHub

  • SimpleRoulette

    A SwiftUI library that lets you create roulette UIs with minimal setup. Configurable segments, animations, and result handlers.

    SwiftSwiftUISwift PackageAnimation
    GitHub

  • AsyncDownSamplingImage

    An AsyncImage extension that performs downsampling during image download to reduce memory usage in SwiftUI apps.

    SwiftSwiftUISwift PackageMemory OptimizationImage Processing
    GitHub

  • GeoHashSwift

    A GeoHash encoding/decoding implementation in Swift, designed for geospatial indexing and location-based queries.

    SwiftSwift PackageGeospatialAlgorithm
    GitHub
—— 05Awards

Notable
moments.