A deep dive into SpacetimeDB's TypeScript SDK and how to wire it into a Next.js 15 App Router application for live visitor tracking and realtime features.
3 min readCurrent systems
Active work,
live signals, and writing.
Featured builds, the latest ranked signal, and recent writing — all in one place.
Featured build
MAINFRAME
Open-source bash stdlib for AI agents. Signals systems-level engineering range. Shows open-source authorship.
Pure bash runtime · Agent working memory primitives
Latest ranked signal
llm-gemini 0.32
<p><strong>Release:</strong> <a href="https://github.com/simonw/llm-gemini/releases/tag/0.32">llm-gemini 0.32</a></p> <blockquote> <ul> <li>New model <code>gemini-3.5-flash</code> for <a href="https://blog.google/innovation-and-
SIMONW · 2h ago · score 68
Publishing system
Building Realtime Apps with SpacetimeDB and Next.js 15
A deep dive into SpacetimeDB's TypeScript SDK and how to wire it into a Next.js 15 App Router application for live visitor tracking and realtime features.
3 min read · spacetimedb · next.js
Open-source ecosystems
Projects I support
Small but important signal: I contribute to and support AI-native developer tooling beyond my own products.
✦ Selected Work
Systems I've Built
Ranked signal feed
Full feed →SIMON· 2h ago↑ HOT
llm-gemini 0.32
68
aidevSIMON· 3h ago↑ HOT
Gemini 3.5 Flash: more expensive, but Google plan to use it for everything
68
aidevTC AI· 4h ago↑ RISING
Google just declared itself a contender in AI design at IO 2026
56
aitechLOB· 6h ago↑ RISING
I am not a Software Engineer
62
devsystemsTC AI· 4h ago↑ RISING
You can now talk to your Gmail inbox, as seen at Google IO 2026
56
aitechVERGE· 2h ago↑ RISING
Wear OS 7 will keep track of deliveries and sports scores on your wrist
42
techai✦ /now
What I'm Doing
Right Now
Building
ACTIVE
PropertyJunk.com — junk removal SaaS platform
ACTIVE
TaxScout.app — commercial real estate tax optimization
WIP
MAINFRAME — open source bash stdlib expansion
WIP
toddwatts.dev — this site
Reading
01Attention Is All You Need (re-read)
02The Pragmatic Programmer — 2nd ed.
03Designing ML Systems — Chip Huyen
Watching
▶
Andrej Karpathy
Neural nets: Zero to Hero
▶
Lex Fridman
Sam Altman ep.
▶
ThePrimeagen
Rust streams
My Setup
EditorVS Code + Claude Code
AIClaude Sonnet 4.5, Pi
RuntimeBun 1.2
DeployVercel






