In the vast expanse of programming languages, Rust has emerged as a considerable paradigm shift. Employing a unique blend of performance characteristics akin to systems programming languages like C or C++, and the safety features more typical of higher-level languages, Rust offers a distinctive development ethos. As you embark on the quest for the perfect Rust developer for your project, the elucidation of certain queries is indispensable.

First, let’s examine the "what" - the nature of Rust programming. Rust is a syntactically similar language to C++ but guarantees memory safety without the need for garbage collection. It eliminates common programming errors due to its unique features such as zero-cost abstraction, move semantics, guaranteed memory safety, threads without data races, trait-based generics, and pattern matching.

In light of the intricate characteristics of Rust, a key question to address with a potential Rust developer is their depth of understanding the unique aspects of the language. Do they comprehend the difference between Rust and other languages in terms of memory management? Can they provide a concise explanation of pattern matching, or the implications of mutable and immutable borrowing?

Their grasp of these concepts is vital as Rust’s unique memory management system allows developers to manually manage memory, providing a level of performance comparable to C and C++, while also providing safety mechanisms to prevent common programming errors that can lead to undefined behavior or security vulnerabilities.

Consider the “where” – the application of Rust. Rust can be utilized in various domains, from system programming, game development, and web assembly to embedded systems. Thus, inquire about the developer's experience in applying Rust in different environments or domains. Have they used Rust in system-level programming, or perhaps in the realm of game development? Understanding the various domains where the developer has applied Rust will provide you with insights into their versatility and adaptability.

The “when” is equally significant and it refers to the time frame in which the developer has been using Rust. A seasoned Rust developer with several years of experience may have a well-rounded understanding of the language's nuances and is likely to provide more efficient problem-solving techniques.

The “how” focuses on the developer's approach to problem-solving. Rust language, with its emphasis on safety and performance, requires a nuanced problem-solving approach. A question worth asking is: How do they approach problem-solving within the constraints and features of Rust? Their response can offer insights into their grasp of the language's nuances and their ability to leverage them effectively.

Lastly, the “why” targets their motivation. Why did they choose to work with Rust? What do they find intriguing about the language? Their answer may illuminate their passion and dedication to Rust, which is crucial for long-term project involvement.

One of the striking characteristics of Rust is its vibrant and passionate community. A potential question could be about their involvement in this community. Have they contributed to the open-source community around Rust? Perhaps they have made contributions to Rust libraries or the language itself? Such contributions often signify a strong understanding of Rust and a commitment to remain updated with its latest developments.

To sum up, finding the right Rust developer for your project is not just about their technical know-how. It’s about their passion for the language, their problem-solving approach, their adaptability, and their commitment to the Rust community. So, ask away, and may you find the perfect Rust developer for your project.