How can you automate the application startup at system boot in Linux?

In Linux, there are several ways to automate the startup of an application during system boot:

1. systemd service — create a unit file in /etc/systemd/system/ describing the service and enable its autostart:

# Create a file /etc/systemd/system/myapp.service
[Unit]
Description=My Application

[Service]
ExecStart=/path/to/application

[Install]
WantedBy=multi-user.target

Then execute:

sudo systemctl enable myapp.service

2. init.d scripts — for systems with SysVinit, add a script to /etc/init.d/ and set up symbolic links in runlevel directories.

3. crontab with @reboot — add a line to crontab:

@reboot /path/to/application

4. Add a call in user startup files — for example, in ~/.bashrc or ~/.profile, but this runs at user login, not at system boot.

The most modern and recommended method is to use systemd services.