We are an application development firm helping our customers develop web & mobile application. We are currently using GitLab for CI/CT/CD. However, we are looking for something more modern, advance & futuristic that will still be in use even after 10 years of supporting the latest technologies/servers of the time. Someone mentioned about Terraform. Any thoughts about which one would be right one to adopt or just continue with Gitlab?
Stick to gitlab you can still use all the other tooling along with it. Terraform is for infrastructure a d they are different things. I use a combination of gitlab, terraform among other tooling.
If you're self-hosting GitLab, then check you're on the latest version since you mentioned it not being modern (in what ways is it not modern?). GitLab is updated very regularly and IMO is definitely a candidate for the best due to it's all-in-one (low cost of integration) design.
I have experience with many CI/CD tools (going right back to CruiseControl!), but not much experience on some of the newer ones (e.g. Spinnaker / Concourse). Recently I came across Tekton, which a lot of good people are rating, so that might be worth a look if you're doing hybrid/multi-cloud with Kubernetes, but I wouldn't replace GitLab unless you're facing some constraining factor that the GitLab team can't help you with - their feature delivery is pretty quick in my experience.