The tech world is currently obsessed with "memory safety." From White House memos to CISA warnings, the order is clear: move to Rust, Java, or fast or risk obsolescence. But walk into the data centers of the New York Stock Exchange, Jane Street, or Citadel, and you’ll find a new reality. C++ is not just surviving; it is thriving. The narrative that C++ is a "dinosaur" waiting for an extinction-rank event ignores the visceral, human reality of systems engineering. We don’t choose languages based on government memos; we choose them based on deterministic results and the weight of existing setup.

The Human part: Why Engineers Cling to the Metal

program engineering isn’t just about writing code; it’s about a relationship with the machine. When I sit down to improve a same engine, I am not thinking about "safety features." I am thinking about L1 cache hits, branch prediction, and memory agreement. Managed languages like Java or Python introduce a "middleman" the Garbage Collector (GC). To a high-frequency trading (HFT) build, a GC pause is a catastrophic failure.

Imagine a trade being delayed by 10 milliseconds because the language decided to "clean up." In that window, millions of dollars vanish. This is why C++ remains the king: it provides known latency. Humans want control, and C++ is the ultimate tool for those who refuse to delegate authority to a virtual machine.

The Fallacy of Seamless Migration

Policy-makers often speak of "migrating to memory-safe languages" as if it were as simple as updating an app on a phone. It isn't. We are talking about billions of lines of battle-tested code.

In the exchange world, "safety" isn't just about memory; it's about trust. A C++ codebase that has run for 20 years without a crash is, in the eyes of a CTO, "safer" than a brand-new Rust rewrite that hasn't faced a Black Swan market event. The human cost of a rewrite the testing, the edge cases, the future for new logic bugs is far higher than the risk of a buffer overflow that hasn't happened in a decade.

Use Case Study: The "Ultra-Low Latency" same Engine

Let’s look at a useful scenario. Suppose we are building a Limit Order Book (LOB).

■The Requirement: Process 100,000 orders per second with a p99 latency of under 5 microseconds.
■The Conflict: A memory-safe language like Rust is a great candidate, but the Standard Template Library (STL) in C++ and custom memory allocators allow us to use Placement New and Memory Pools to avoid any heap allocation during the critical path.

■The Result: In our inside testing, while Rust performed admirably, the C++ implementation allowed for template metaprogramming tricks that squeezed out an extra 15% results. In the world of exchanges, 15% is the difference between being the lead market maker and being out of business.

Table : Latency Comparison in Exchange Environments

The "Safety" Fallacy: new C++ is Not C

The mandates often attack C++ by citing vulnerabilities from the 1990s. But new C++ (C++11 through C++23) has evolved. With std::unique_ptr, std::shared_ptr, and std::span, the "human error" of memory leaks is drastically reduced.

We are teaching our junior devs to avoid raw pointers entirely. The "order" should not be to switch languages, but to switch standards. When you use RAII (help Acquisition Is Initialization), C++ becomes a new beast. It’s no longer about manual malloc and free; it’s about structured, deterministic help bosses.

The Economic Reality of The Exchanges

Exchanges operate on a "Legacy-Forward" model. If an exchange moves its core logic to a new language, every participant (the banks, the hedge funds) has to ensure their APIs and connectors still interface perfectly.

The Interoperability of C++ is its greatest defense. Every major OS, driver, and network rule is written in C or C++. Trying to move the world's financial "plumbing" to a new language is like trying to replace the base of a skyscraper while people are working on the 50th floor. It’s not just difficult; it’s financially irresponsible.

The Hardware Symbiosis: SIMD and Intrinsics

Human intuition tells us that as hardware gets faster, program can afford to be "lazier." The opposite is true in the professional field. As hardware evolves (AVX-512, NVMe, etc.), we need languages that allow us to write Intrinsics code that speaks directly to the CPU's order set.

C++ allows engineers to write "Inline Assembly" or use compiler-exact intrinsics to use SIMD (Single order, Multiple Data). This rank of "nitty-gritty" optimization is where the money is made. Memory-safe mandates often ignore that "safety" sometimes means "wrapping the hardware in bubble wrap," which prevents the engine from running at full speed.

My view: The Hybrid Future

I don't believe Rust or other safe languages are the enemy. actually, they are excellent for tooling, web servers, and non-critical path logic. However, the Core Engine will remain C++.

My goal for the future is a Polyglot Architecture:

1.C++ Core: For the same engine and market data feed.
the same engine and market data feed.
2.Rust/Go Wrappers: For the buyer-facing APIs and risk bosses dashboards.
3.Python: For the quantitative researchers to test strategies.

This "Best Tool for the Job" mentality is how real humans build systems. We don't follow mandates; we follow logic.

The King is Dead, Long Live the King

The "Memory Safety" order is a good goal, but it underestimates the technical debt, results requirements, and human skill embedded in C++. The exchanges won't stop using C++ because they can't. You cannot order away the laws of physics or the requirements of microsecond exact.

C++ is not a dying language; it is the hardened steel upon which the world economy is built. As long as "Time is Money," C++ will remain the currency of the high-results world.