Journal

Notes from things that broke.

Short write-ups on correctness, infrastructure and the specific bugs that changed how I build. RSS.

27 October 2026

Replication lag: read replicas and read-your-writes consistency

Why read replicas return stale data after a write, how replication lag works, and three ways to get read-your-writes consistency.

7 min · Databases · Scaling · PostgreSQL · Architecture

26 October 2026

Mistral Voxtral 3: speech models and a voice agent SDK

Mistral Voxtral 3 adds transcription in 50 languages, realtime TTS and a voice agent SDK. How the pipeline works, what it costs and what to check.

6 min · AI · Voice · Agents · APIs

25 October 2026

Why JSON.stringify drops undefined, Map, Set and Date types

JSON.stringify silently drops undefined, empties Map and Set, and turns Dates into strings. Here is every rule and how to serialize safely.

6 min · JavaScript · JSON · Debugging

24 October 2026

RegExp.escape: build safe dynamic regex in JavaScript

RegExp.escape turns any string into a literal regex fragment. How it works, where the old escape helper breaks, and where you can use it today.

6 min · JavaScript · Web Platform · Node.js

23 October 2026

Idempotency keys: how to make API retries safe

Idempotency keys let clients retry API requests without double charges or duplicate orders. Learn how they work, how to store them and the races to avoid.

7 min · Scaling · APIs · Reliability · Databases

22 October 2026

Inception Mercury 3: how a diffusion LLM hits 1,000 tokens/s

Inception Mercury 3 is a diffusion LLM that refines whole drafts in parallel. How it works, its API and specs, and when its speed matters for your app.

6 min · AI · LLMs · APIs · Performance

21 October 2026

Uint8Array toBase64 and fromBase64: native base64 in JavaScript

Uint8Array.toBase64() and fromBase64() encode and decode bytes natively, with hex, base64url and buffer options. How they work and where they run.

6 min · JavaScript · Web Platform · Node.js

20 October 2026

Circuit breaker pattern: how it works and when it should trip

The circuit breaker pattern stops calls to a failing dependency, fails fast and probes for recovery. Learn the three states, trip rules and fallbacks.

7 min · Scaling · Reliability · Architecture

19 October 2026

JetBrains Mellum2.1: a fast open model for coding agents

JetBrains Mellum2.1 is a 12B open MoE model with 2.5B active parameters for coding agents. How it works, what changed, and how to run it.

6 min · AI · LLMs · Open Models · Agents

18 October 2026

Why await inside forEach doesn't wait, and what to use instead

Using await inside forEach doesn't wait: forEach ignores the promises, so code runs early and errors escape. Here's why, plus for...of and Promise.all fixes.

6 min · JavaScript · Async · Debugging

17 October 2026

Customizable select: style a native <select> with base-select

Customizable select lets you style a native <select> with CSS using appearance: base-select, rich options and selectedcontent. Here's how it works.

6 min · CSS · HTML · Web Platform · Accessibility

16 October 2026

Transactional outbox pattern: reliable events without dual writes

The transactional outbox pattern keeps database writes and published events in sync. How it works, polling vs CDC, and handling duplicates.

7 min · Architecture · Scaling · Reliability · Databases

15 October 2026

Claude Haiku 5.5: pricing, effort levels and migration

Claude Haiku 5.5 is Anthropic's cheap, fast model with a 1M context and adjustable effort. What it costs, how effort works and what breaks when you migrate.

6 min · AI · LLMs · Anthropic · APIs

14 October 2026

JavaScript text modules: import files as strings with type text

JavaScript text modules let you import a .txt, .sql or shader file as a plain string with type: "text". Here is how they work and where they run.

5 min · JavaScript · Web Platform · Node.js

13 October 2026

Exponential backoff with jitter: retries that don't cause outages

Exponential backoff with jitter spreads out retries so failed clients don't hammer a recovering service. How it works, which jitter to use, and what to retry.

7 min · Scaling · Reliability · Architecture

12 October 2026

EmbeddingGemma 2: Google's open multimodal embedding model

EmbeddingGemma 2 embeds text, code, images, audio and video in one space and runs on-device. How it works, task prefixes, and Matryoshka sizes.

5 min · AI · Embeddings · RAG · Open Models

11 October 2026

Why fetch() doesn't reject on 404 or 500, and how to fix it

JavaScript fetch() resolves on 404 and 500 errors, so your catch block never runs. Here's why, and a small wrapper that checks response.ok properly.

6 min · JavaScript · Node.js · Debugging

10 October 2026

ariaNotify(): screen reader announcements without live regions

ariaNotify() lets you make screen readers speak from JavaScript with one call, no hidden live region needed. Here is how it works and when to use it.

5 min · Accessibility · Web Platform · JavaScript

9 October 2026

Consistent hashing: how it works and why virtual nodes matter

Consistent hashing lets you add or remove cache servers while moving only a small share of keys. Here is how the ring, virtual nodes and hash slots work.

6 min · Scaling · Caching · Architecture

8 October 2026

OpenAI Ultrafast mode: how the GPT-6 Astra tier works

OpenAI Ultrafast mode makes GPT-6 Astra stream output up to several times faster at six times the price. How it works, what it costs and when to use it.

6 min · AI · LLMs · OpenAI · Performance

← Back to Syed’s work

Notes from things that broke.Notes from things that broke.

Replication lag: read replicas and read-your-writes consistency

Mistral Voxtral 3: speech models and a voice agent SDK

Why JSON.stringify drops undefined, Map, Set and Date types

RegExp.escape: build safe dynamic regex in JavaScript

Idempotency keys: how to make API retries safe

Inception Mercury 3: how a diffusion LLM hits 1,000 tokens/s

Uint8Array toBase64 and fromBase64: native base64 in JavaScript

Circuit breaker pattern: how it works and when it should trip

JetBrains Mellum2.1: a fast open model for coding agents

Why await inside forEach doesn't wait, and what to use instead

Customizable select: style a native <select> with base-select

Transactional outbox pattern: reliable events without dual writes

Claude Haiku 5.5: pricing, effort levels and migration

JavaScript text modules: import files as strings with type text

Exponential backoff with jitter: retries that don't cause outages

EmbeddingGemma 2: Google's open multimodal embedding model

Why fetch() doesn't reject on 404 or 500, and how to fix it

ariaNotify(): screen reader announcements without live regions

Consistent hashing: how it works and why virtual nodes matter

OpenAI Ultrafast mode: how the GPT-6 Astra tier works

Notes from things that broke.Notes from things that broke.

Replication lag: read replicas and read-your-writes consistency

Mistral Voxtral 3: speech models and a voice agent SDK

Why JSON.stringify drops undefined, Map, Set and Date types

RegExp.escape: build safe dynamic regex in JavaScript

Idempotency keys: how to make API retries safe

Inception Mercury 3: how a diffusion LLM hits 1,000 tokens/s

Uint8Array toBase64 and fromBase64: native base64 in JavaScript

Circuit breaker pattern: how it works and when it should trip

JetBrains Mellum2.1: a fast open model for coding agents

Why await inside forEach doesn't wait, and what to use instead

Customizable select: style a native <select> with base-select

Transactional outbox pattern: reliable events without dual writes

Claude Haiku 5.5: pricing, effort levels and migration

JavaScript text modules: import files as strings with type text

Exponential backoff with jitter: retries that don't cause outages

EmbeddingGemma 2: Google's open multimodal embedding model

Why fetch() doesn't reject on 404 or 500, and how to fix it

ariaNotify(): screen reader announcements without live regions

Consistent hashing: how it works and why virtual nodes matter

OpenAI Ultrafast mode: how the GPT-6 Astra tier works

Notes from things that broke.

Notes from things that broke.