Pull three items off the Inventory and rewrite each one as what you did, why it mattered, and what it prevented or enabled.

Pick three items that can be said out loud. Not the most impressive three. The three you can describe without breaking an NDA or naming a client.

Then rewrite each one in the shape: what you did, why it mattered, what it prevented or enabled.

Written badly: "Optimized a slow query."

Written well: "Cut a nightly report from forty minutes to ninety seconds by fixing one index, which meant the ops team stopped starting their day late."

Same work. The second one is specific, and specific is rare. It also names who was affected, which is what makes a stranger care.

Done looks like three items of one or two sentences each. Not paragraphs. If you are writing a paragraph you are explaining the implementation, and nobody asked.

The one mistake is the reason most developers stall here: worrying it sounds like bragging. It sounds like bragging when it is vague and about you. "I am a strong performer" is bragging. "The export job was timing out for our three biggest customers and now it is not" is a fact with a number attached. Facts do not brag. Put the work in the subject of the sentence and yourself in the verb.