Hi all, new to platform engineering, but looking for any guidance/recommendation for making a technology choice to build an internal developer portal (UI + platform orchestrator/backend), while considering vendor lock in..

Welcome. Few things to consider before selecting a specific platform/tool/architecture: Have you identified any key objectives or benefits you want to gain from said platform? (eg faster software deployment times vs faster developer onboarding...) How large is the potential user base / software estate? One team vs multiple etc. Adoption is usually a big sticking point so getting clear criteria from the major stakeholders will help ensure you are moving down the right path. It sounds like you/your team is pro-open source, and the most popular IDP option I'm aware of is Backstage (which is also open source). Worth noting that Backstage is a framework and it does require a decent amount of uplift to deploy and maintain. I'm aware of two vendors who offer commercial offerings that reduce this overhead (self plug - founder @ Arctir.com and we are one of the aforementioned vendors) and have their own spin on things. This is also likely the safest route if you are concerned about lock-in. There are also a number of solid proprietary offerings in the space, but I'd start with thinking through the goals / objectives first. Happy to chat about that if you need ideas.

These are some excellent points, especially around adoption. Spotify famously sees 90% adoption of Backstage internally, but only 10% adoption externally. That means you could end up spending a lot of FTE resources for little payback. The key is to find a few specific, easy to explain use cases that solve real pain and focus on fixing those first to try and bolster cultural buy-in. Do you have strict requirements to build vs. buy? As Paul mentioned, Backstage is essentially a code repo that you need to customize, build, and maintain. Depending on the size of your engineering team, this can become more expensive than just buying something, like Cortex.io (transparency - for whom I run Developer Relations) or another commercial SaaS IDP.