Skip to content
effidevFlutter · Cloudflare edge · Cloud cost optimization
English

About effidev

effidev is a personal engineering blog about the things I actually build with: Flutter, Cloudflare's edge platform (Workers, D1, R2, KV, Durable Objects) and cutting cloud bills. Everything here is written in Korean first and then translated.

Who runs this

Seongjin Kim (김성진) — a freelance full-stack developer working on client projects. effidev is my personal blog, not a company one.

I also build and operate the tools linked from the home page — the scheduling and publishing services for Instagram, Threads, X, YouTube and TikTok. Most posts here come out of problems I actually hit while building those, or on client work. There is no editorial team, and no sponsored or paid posts.

Experience
10 years
Main stack
AWS · Cloudflare · Flutter · TypeScript
Client work
11 commerce apps · 3 B2B full-stack projects
Profile
LinkedIn — sungjinkimflutter

The topics here cluster around Flutter and Cloudflare because that is what I actually get paid to build. I don't write about stacks I haven't shipped with.

How posts are written

  • Topics come from problems that came up in real work, or from changes that force code to be rewritten.
  • Facts, version numbers, pricing and API behaviour are checked against primary sources — official release notes, specifications and pricing pages — not against secondhand articles.
  • Code samples are written to run on the versions named in the post.
  • When something is uncertain, the post says so rather than guessing.
  • Posts are updated when the underlying product changes; corrections are made in place.

I use AI tooling while drafting and translating, the same way I use it while coding. Every claim, number and code sample is verified against the primary source before publishing — that verification is the part that decides whether a post ships.

Contact

Corrections, questions and service access requests are all welcome. The fastest channel is an Instagram DM.

Found an error? Tell me which post and which line. I would rather fix it than leave it standing.