https://www.dexterindustries.com/howto/run-a-program-on-your-raspberry-pi-at-startup/.

sudo nano /etc/systemd/system/justine.service

[Unit]
Description=Met en route l'installation Justine

[Service]
Type=simple
WorkingDirectory=/home/pi/Justine/
ExecStart=/home/pi/Justine/./test 6
Restart=on-failure
RestartSec=10
User=pi
Group=pi

[Install]
WantedBy=multi-user.target

sudo systemctl enable justine.service

sudo systemctl status client_test_a.service