ことで details
write + by doing
kaku koto de
by doing; through doing — names the action that brings the result about
meaning: by writing
毎日少しずつ続けることで、力がついてくる。
mainichi sukoshi zutsu tsuzukeru koto de, chikara ga tsuite kuru.
You build strength by continuing a little at a time every day. neutral
早めに対応したことで、被害を最小限に抑えられた。
hayame ni taiou shita koto de, higai o saishougen ni osaerareta.
Because we responded early, the damage was kept to a minimum. neutral
Examples
by doing X — the action is what produces the result; a general statement can put a natural process there rather than an act
毎日少しずつ続けることで、力がついてくる。
mainichi sukoshi zutsu tsuzukerukotode, chikara ga tsuite kuru.
You build strength by continuing a little at a time every day. neutral
先に予約しておくことで、待たなくてすむんだって。
saki ni yoyaku shite oku koto de, matanakute sumu n datte.
Apparently booking ahead means you don't have to wait. casual
気温が上がることで、山の雪が一気に溶け出す。
kion ga agaru koto de, yama no yuki ga ikki ni tokedasu.
A rise in temperature sets the mountain snow melting all at once. neutral
手続きをオンラインに移すことで、窓口の混雑を大幅に減らすことができます。
tetsuzuki o onrain ni utsusu koto de, madoguchi no konzatsu o oohaba ni herasu koto ga dekimasu.
Moving the procedure online lets us cut congestion at the counter considerably. formal
owing to having done X — the past form looks back and credits the outcome to something already done
早めに対応したことで、被害を最小限に抑えられた。
hayame ni taiou shita koto de, higai o saishougen ni osaerareta.
Because we responded early, the damage was kept to a minimum. neutral
一度失敗したことで、かえって慎重になれた気がする。
ichido shippai shita koto de, kaette shinchou ni nareta ki ga suru.
Having failed once, I feel I actually became more careful for it. neutral
Formation
{V}ことでattaches to dictionary form{V-ta}ことでattaches to た-form
Related patterns
Similar
によって takes a NOUN and stretches well past means — it also marks an agent (職人によって建てられた) and a "it depends" reading (人によって違う); ことで spells the means out as an action and does only that, so ×人ことで違う and ×職人ことで建てられた are both out.
で marks the means as a thing you use (電話で知らせる); ことで has to spell out a whole action instead, which is what lets it name something with no noun for it — 先に予約しておくことで.
Lookalikes
The same string ことで, and what sits in front decides it — a verb makes it the means an outcome came about by (予約することで待たずに済む), a noun plus の makes it the matter under discussion (息子のことでご相談が); one is how, the other is about what.