```ts
/** An append-only log of timestamped events. */
export class EventLog {
  #events: Event[] = [];

  /** Append one event. */
  record(event: { name: string; timestamp: number }) {
    this.#events.push({ ...event });
  }

  /** Every event at or after the given timestamp, in insertion order. */
  since(timestamp: number) {
    return [...this.#events].filter((event) => event.timestamp >= timestamp);
  }
}
```