A logo wall usually means one of three things: an approved reference, one small piece of work dressed up as a partnership, or a mark nobody asked permission to use. Only the first is worth anything to you, and it takes the longest to get. Until a case study is approved and has a result we can state honestly, this space stays empty rather than getting filled.
In the meantime: ask us in a call. We will talk through specific systems we have integrated and problems we have fixed, and arrange a reference conversation under NDA where the client agrees to one.