[ Blog_Posts ]

Testing Real-World Go Backends Isn't What Many People Think

The unit-vs-integration framing is a junior lens. Production Go backends need a different taxonomy: deterministic tests, contract tests, race tests, and fidelity tests. The ones that actually catch production bugs.

2026-02-18 Harrison Guo 10 min read golang go testing backend-engineering distributed-systems race-conditions contract-testing production software-engineering

Observability and Cost Attribution: Why One Pipeline Isn't Enough

Tracing systems optimize for signal-to-noise. Billing systems optimize for accuracy and auditability. They look similar and they are not the same thing. A dual-path architecture for running both without cross-contamination.

2026-02-15 Harrison Guo 10 min read observability billing cost-attribution opentelemetry distributed-systems architecture backend-engineering system-design metrics tracing

Go Context in Distributed Systems: What Actually Works in Production

context.Context is not documentation, not a metadata bag, and not optional. A production-hardened guide to cancellation propagation, the background-goroutine trap, and the patterns that keep services alive when downstreams slow down.

2026-02-13 Harrison Guo 9 min read golang go context concurrency distributed-systems cancellation goroutines errgroup production backend-engineering

Go's Concurrency Is About Structure, Not Speed: chan and context as Lifecycle Primitives

After a few years writing production Go, I stopped thinking of chan as a data pipe and context as a parameter. They're both lifecycle primitives — chan draws the boundary of 'how many alive', context draws the boundary of 'when to die'. Here's why that mental model changes the code you write.

2025-11-21 Harrison Guo 10 min read golang go concurrency channels context backpressure worker-pool distributed-systems backend-engineering go-design

IronSys: A Production Blueprint for Modern Concurrency

After Four Pillars of Concurrency, the natural question: what does a system actually look like when it uses all of them deliberately? IronSys is a composite blueprint — the concurrency architecture I'd build today if I were starting over, with the trade-offs each choice buys.

2025-10-22 Harrison Guo 10 min read concurrency system-design golang architecture distributed-systems backend-engineering csp actors production

From Locks to Actors: The Four Pillars of Modern Concurrency

Most engineers still reach for the mutex. That's one of four options, and usually not the best one. A working engineer's map of shared-state, CSP, actors, and STM — and when each is the right tool.

2025-10-20 Harrison Guo 10 min read concurrency system-design golang erlang rust distributed-systems csp actors stm backend-engineering

Why Go Handles Millions of Connections: User-Space Context Switching, Explained

Go isn't magic and it isn't faster than Java. It just stops asking the kernel to help. A first-principles look at goroutines, 2KB stacks, and why high-frequency trading engines chase the exact same answer.

2025-10-13 Harrison Guo 7 min read golang go concurrency distributed-systems goroutines scheduler performance user-space-networking kernel-bypass backend-engineering

Rust vs C Assembly: Complete Performance and Safety Analysis - Panic or Segfault?

Deep dive comparison of Rust and C at assembly level. See how Rust's memory safety, bounds checking, and zero-cost abstractions compare to C's raw performance through actual GDB debugging sessions and assembly analysis.

2025-07-08 Harrison Guo 12 min read rust c assembly performance memory-safety systems-programming gdb debugging benchmarks

Legacy Compatibility Lab: My Full Stack for Reviving Dead Software

A comprehensive documentation of my virtualized environment stack designed to analyze, patch, and rebuild legacy Windows applications — from XP-era binaries to modern Win10 apps needing backwards compatibility.

2025-05-30 Harrison Guo 3 min read WinXP Win7 Visual Studio Delphi Software Revival Virtual Machines

Placed 2nd at BSides Vancouver 2025 Blue Team CTF – With Just ChatGPT and Stubbornness

How I placed 2nd solo at BSides Vancouver 2025 Blue Team CTF using only ChatGPT and Splunk: threat hunting, incident response, registry forensics, and AI-driven analysis.

2025-05-25 Harrison Guo 3 min read BSides Vancouver Blue Team CTF Splunk Threat Hunting Incident Response Forensics Malware Analysis Windows Event Log Registry Forensics AI Security ChatGPT Security Automation

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