We have been for more than 6 years in market. We specifically develop data science and full stack development work. But most of our work and specially Projects that are worth showing are under NDA.
what should we do under this situation ? To get new Clients?
Ah, the classic NDA on SaaS -developed programs. this is probably the trickiest approach to company and experience validation that an entrepreneur has to go through.
Thankfully, I have a solution for you; lean in close.
You're thinking of how to validate your skill-set to clients and that's great, but you don't need to show a final product- you can show and explain the thinking and practice behind the product.
Anyone can present a MVP or program, but not everyone can talk about how they approach a problem, the steps they take and aspects/data they look at before they even start.
Have great people on your team? That's one of the most important areas of a development proposal. Showcase your team as a crucial part of a bigger solution. Show clients that the program/service/practice will do what it's meant to; the real heart is the ability to show how you'll exceed their needs and great solutions like no other company.
Show your thinking.
Show your approach.
Show the parts that don't go into the project.
I agree with William, that you can describe the value of your process and steps you take to ensure client satisfaction. But there's also nothing that should be stopping you from getting testimonials from your previous clients. There are seven or eight different approaches to getting testimonials, and the set of questions you ask does not have to reveal anything about how your software works.
Think about questions like:
1) how much time was saved after the new software was put in place
2) what kind of things has having this technology enabled you to do that were a struggle before (e.g., speed of delivery, higher profit per job, cut steps, redirect internal resources, etc.)
By agreement with your NDA partners. Collaboratively explain your dilemma. Did you offer them a discount for the use of e.g. slides of older work?
Otherwise you cannot use that work as you have already agreed not to.