Smart switches, dumb bulbs if you don’t need colour/temperature/brightness support. Cheapest way to go is probably Zigbee using Zigbee2MQTT or ZHA
Shelly
I use the vintage ones as they look nice.
I have 12 of them because my house wiring is 💩 so I can't get smart switches to work properly
They're wifi and can operate with the Shelly integration and / or MQTT. No need for an app, they have their own wifi when you first power them up to configure them.
The only reason I let them loose on the internet is to update their firmware, then I isolate them again.
I also have a pair of Lifx bulbs in the bedroom as they're inside shades so it's more about the RGB colour for sunrise / sunset than their visual appeal as a bulb.
homeassistant
Home Assistant is open source home automation that puts local control and privacy first.
Powered by a worldwide community of tinkerers and DIY enthusiasts.
Home Assistant can be self-installed on ProxMox, Raspberry Pi, or even purchased pre-installed: Home Assistant: Installation
Discussion of Home-Assistant adjacent topics is absolutely fine, within reason.
If you're not sure, DM @GreatAlbatross@feddit.uk