The Bucket Is the Log: Building an Append-Only Log on Object Storage in Go
Build an append-only log on object storage in Go using immutable segments, a bounded catalog, writer fencing, and replay by LSN or timestamp—without a broker.
Writing
Notes and visual explanations about Go, distributed systems, databases, performance, and software engineering.
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2026
Go singleflight: Cancellation and Shutdown
Learn how Go singleflight prevents cache stampedes, why caller cancellation gets tricky, and how to safely cancel and drain shared work during shutdown.
Building a Key-Value Database on S3 in Go
How an LSM tree gives us the right building blocks, and where object storage changes the design.
2025
Timing Wheels: Expiring 10 Million Keys in Go
How hierarchical timing wheels expire millions of cache entries efficiently in Go without periodic O(n) scans or a timer per key.
2020
Illustrated Tales of the Go Runtime Scheduler
An illustrated tour of Go’s runtime scheduler: operating-system foundations, the G-M-P model, work stealing, preemption, and scheduler traces.
How to mock? Go Way.
How to use small interfaces, structs, and hand-written test doubles to isolate dependencies and write focused unit tests with Go's standard library.
2019
An Introduction to the 99th Percentile for Programmers
Why averages and medians hide tail latency, how the 99th percentile exposes it, and how to calculate and interpret p99 with examples in Go.
Communicating Sequential Processes in Go
A concise introduction to CSP through processes, synchronous input and output, guarded commands, and the ideas that shaped Go channels.
A Visual Guide to Go's Memory Allocator
A visual guide to Go's memory allocator, from virtual memory and TCMalloc to mspan, mcache, mcentral, mheap, arenas, and object allocation.
2018
A Closer Look at Go's Type System
A practical guide to Go's named, unnamed, and underlying types, with examples of assignability, conversion, type identity, and compatibility.
Diving Deep into Go Channels
A source-level tour of Go channels: hchan, sudog, wait queues, buffered storage, blocking sends and receives, select, and goroutine wake-ups.
The Performance Cost of CORS in Single-Page Applications
How CORS preflight requests add latency to cross-origin APIs, why URL-specific preflight caching may not help, and what SPA designers should consider.
Building a Single Sign-On Server in Node.js
Build a minimal token-based single sign-on flow in Node.js, covering redirects, global and local sessions, consumer validation, and single sign-off.
The Cost of Parameter Destructuring in JavaScript
Compare ordinary parameters with object destructuring in Node.js through V8 bytecode, heap usage, garbage collection, and microbenchmarks.
Implementing call(), apply(), and bind() in JavaScript
Reimplement JavaScript's call(), apply(), and bind() to understand this binding, variable arguments, return values, constructor behavior, and edge cases.
The Missing Introduction to React
Build the ideas behind React step by step: reusable components, state, setState, declarative rendering, and efficient DOM updates.
Building Express.js from Scratch, Part 1
Build a small Express-like framework in Node.js, starting with an HTTP server and GET routes, then adding Router, Route, and Layer abstractions.
2017
A Gentle Introduction to JavaScript Prototypes
How JavaScript's prototype chain works, how constructor prototype properties differ from object [[Prototype]] links, and how inheritance resolves properties.
Diving Deep into Node.js Buffers
How Node.js stores and transmits binary data with Buffer, including allocation APIs, memory behavior, performance, and the internal 8 KB slab pool.
setTimeout vs setImmediate in Node.js
Why setTimeout(0) and setImmediate() can run in either order, explained through Node.js event-loop phases, libuv, clock updates, and process timing.
2016
The Basic Relational Mathematics Behind SQL
A short introduction to relations, Cartesian products, schemas, attributes, and how those mathematical ideas are represented as SQL tables.
Mutable Default Arguments in Python
Why Python evaluates default arguments once, how mutable defaults retain state between calls, and how the None sentinel pattern avoids the problem.
Understanding Python's Object Model, Part 1
An introduction to CPython's object representation through PyObject, PyVarObject, reference counting, type pointers, and variable-sized objects.
Private Fields Are Class-Private in Java
Why code inside a Java class can access private fields on another instance of the same class, with examples using mutation and equals().
Efficient Factorial Algorithms
A comparison of recursive, iterative, paired-multiplication, and prime-decomposition approaches to computing large factorials in Python and Java.