What are you all using for long term project/conversational memory these days?

I am trying to learn more about long-term memory and how people are handling that nowadays. Historically, I have used a mixture of paid cloud AI services (ChatGPT, Gemini, OpenRouter API) and my own local inference. However, at this point, I'm convinced that ChatGPT is deliberately throttling my use and causing service disruptions to extract my monthly fee while minimizing actual compute spent. I would like to switch away from ChatGPT altogether, but one of the few things keeping me there is conversational/project memory that has years of data containing hundreds of chats. Setting aside all of the things that I hate about ChatGPT, one thing that I can say they do incredibly well is conversational memory. I have many long-running projects that it maintains a very solid overall understanding of, in addition to being able to perform precise recall (e.g. asking about a highly specific detailed change that was made months ago). My local LLMs (current daily drivers are Deepseek V4 Flash and Qwen 3.8 27B) are very capable of most tasks that don't require long term memory, but the moment I get into very large software projects everything breaks down, because just understanding the code base fills up most of the LLM context, and I can't have hours of design/architectural planning discussions with it where it will remember my overall project goals when I am making new changes. I need tools for long-term conversational memory that will let me work on a large software project locally, while maintaining a coherent sense of the big picture. I am a person that has many interests including not only programming projects but also circuit design / electronics projects, physiology/pharmacology/biophysics, mathematics, car maintenance, ecology, history, etc. .... I want conversational memory that can keep track of all of these conversations over years and when I say "Hey, remember that DIY EKG circuit we were building a few months back? Give me a summary of that conversation to get me back up to speed" How do you all create AI assistants that maintain years worth of conversations like this? Have you managed to find anything that works as well or better than the memory from cloud AI providers like ChatGPT, Claude, etc? Thanks!