Flutter (Front End)

Flutter is an open source framework by Google for building beautiful, natively compiled, multi-platform applications from a single codebase. From their website

We choose Flutter as our framework to develop our mobile application because of

• Cross-Platform Consistency: we can build for both IOS and androin using the same code.
• Modular Architecture: widgets is very easy to work with.
• Expressive Code: the programming language Dart is simple, fast enough, static type, and has an interesting sound null safety.
• Extensive Plugin Ecosystem: the community is big, so we have a lot of other people's code to use.

Rust (Both on Collar Software and Lambda)

According to their website Rust has good

• Performance: Rust is blazingly fast and memory-efficient: with no runtime or garbage collector, it can power performance-critical services, run on embedded devices,
  and easily integrate with other languages.
• Reliability: Rust’s rich type system and ownership model guarantee memory-safety and thread-safety — enabling you to eliminate many classes of bugs at compile-time.
• Productivity: Rust has great documentation, a friendly compiler with useful error messages, and top-notch tooling — an integrated package manager and build tool, smart multi-editor support with auto-completion and type inspections, an auto-formatter, and more.

We choose Rust as our main language for developing backend side code, because of

• It's fast, memory safe, which are good for embeded devices.
• It's a joy to write, cargo is super easy to work with.
• Rust community is growing, and many big companies seems to want to adopt it (e.g. Microsoft seeks Rust developers to rewrite core C# code).
• Rust's ownership model and fearless concurrency support make it well-suited for building scalable and concurrent backend systems.