1. Create user service in user's home directory ex. /home/debian/.config/systemd/user/

Example:

[Unit]
Description=my npm app
After=network.target

[Service]
ExecStart=/usr/bin/npm start
WorkingDirectory=/home/debian/mynpmapp/

[Install]
WantedBy=default.target

2. From root enable lingering so that it persists over reboots and logouts

loginctl enable-linger username

3. Use systemctl –user start|stop <servicename> to run service

apt install dbus-user-session

In .bashrc of the user put:

export XDG_RUNTIME_DIR=/run/user/$(id -u)
export DBUS_SESSION_BUS_ADDRESS="unix:path=${XDG_RUNTIME_DIR}/bus"

then logout and login again.

• Debian 10

• https://wiki.archlinux.org/index.php/Systemd/User#Automatic_start-up_of_systemd_user_instances
• https://serverfault.com/questions/841099/systemd-grant-an-unprivileged-user-permission-to-alter-one-specific-service