Use a vegetable peeler or sharp knife to thinly slice the cucumbers into rounds or matchsticks, then transfer them to a mixing bowl.
In a small bowl, whisk together soy sauce, vinegar, sugar, and minced garlic until the sugar dissolves completely and the dressing is smooth.
Pour the dressing over the sliced cucumbers, tossing gently to coat all the pieces evenly.
Drizzle chili oil over the top of the salad, then use a spoon or tongs to toss everything together, allowing the chili oil to distribute evenly and coat the cucumbers with a glossy sheen.
Add a pinch of salt to taste and toss once more to finalize the flavor balance.
Transfer the finished cucumber salad to a serving bowl and serve immediately for the freshest crunch and flavor.