How to optimize the loading of web application developed with Angular and Springboot

Question

I've developed an web application with Angular, Springboot and Jhipster. I want to know if it's possible to optimize the loading of the application. if yes how can I do that.

Here is the results I get

Here is navbar and home components (loaded first).

navbar.component.ts

    import { Component, OnInit } from '@angular/core';
import { Router } from '@angular/router';
import { NgbModalRef } from '@ng-bootstrap/ng-bootstrap';
import { JhiLanguageService } from 'ng-jhipster';

import { ProfileService } from '../profiles/profile.service';
import { JhiLanguageHelper, Principal, LoginModalService, LoginService } from '../../shared';

import { VERSION, DEBUG_INFO_ENABLED } from '../../app.constants';

@Component({
    selector: 'jhi-navbar',
    templateUrl: './navbar.component.html',
    styleUrls: [
        'navbar.css'
    ]
})
export class NavbarComponent implements OnInit {

    inProduction: boolean;
    isNavbarCollapsed: boolean;
    languages: any[];
    swaggerEnabled: boolean;
    modalRef: NgbModalRef;
    version: string;

    constructor(
        private loginService: LoginService,
        private languageHelper: JhiLanguageHelper,
        private languageService: JhiLanguageService,
        private principal: Principal,
        private loginModalService: LoginModalService,
        private profileService: ProfileService,
        private router: Router
    ) {
        this.version = VERSION ? 'v' + VERSION : '';
        this.isNavbarCollapsed = true;
        this.languageService.addLocation('home');
    }

    ngOnInit() {
        this.languageHelper.getAll().then((languages) => {
            this.languages = languages;
        });

        this.profileService.getProfileInfo().subscribe((profileInfo) => {
            this.inProduction = profileInfo.inProduction;
            this.swaggerEnabled = profileInfo.swaggerEnabled;
        });
    }

    changeLanguage(languageKey: string) {
      this.languageService.changeLanguage(languageKey);
    }

    collapseNavbar() {
        this.isNavbarCollapsed = true;
    }

    isAuthenticated() {
        return this.principal.isAuthenticated();
    }

    login() {
        this.modalRef = this.loginModalService.open();
    }

    logout() {
        this.collapseNavbar();
        this.loginService.logout();
        this.router.navigate(['']);
    }

    toggleNavbar() {
        this.isNavbarCollapsed = !this.isNavbarCollapsed;
    }

    getImageUrl() {
        return this.isAuthenticated() ? this.principal.getImageUrl() : null;
    }
}

home.component.ts

import { Component, OnInit } from '@angular/core';
import { NgbModalRef } from '@ng-bootstrap/ng-bootstrap';
import { EventManager } from 'ng-jhipster';

import { Account, LoginModalService, Principal } from '../shared';

@Component({
    selector: 'jhi-home',
    templateUrl: './home.component.html',
    styleUrls: [ 'home.css' ]
})
export class HomeComponent implements OnInit {
    account: Account;
    modalRef: NgbModalRef;

    constructor(
        private principal: Principal,
        private loginModalService: LoginModalService,
        private eventManager: EventManager
    ) {}

    ngOnInit() {
        /*  this.principal.identity().then((account) => {
            this.account = account;
        }); */
        this.registerAuthenticationSuccess();
    }

    registerAuthenticationSuccess() {
        this.eventManager.subscribe('authenticationSuccess', (message) => {
            this.principal.identity().then((account) => {
                this.account = account;
            });
        });
    }

    isAuthenticated() {
        return this.principal.isAuthenticated();
    }

    login() {
        this.modalRef = this.loginModalService.open();
    }
}

home.component.html

<div class="row">
    <div class="col-md-3">
        <!-- <span class="hipster img-fluid img-rounded"></span> -->
    </div>
    <div class="col-md-9">
        <h1 class="display-4">Bienvenue!</h1> 
    </div>
</div>