David's Internet
1 language| Type | Portfolio search engine |
|---|---|
| Replicas | 12 |
| Interactive demos | 18 |
| Repository | Replicates |
| Website | david-internet.vercel.app |
| Demo video | 23 seconds, on the YouTube replica |
David's Internet is a search engine over software David built: working replicas of products such as Linear, Notion and YouTube, each in its own folder of the Replicates repository, and interactive demos of coursework and lab work hosted on the search site itself. This encyclopedia serves as the index to those projects. Every replica and every shipped demo has an article, linked from the tables below.
The search engine went live in September 2026 at david-internet.vercel.app. Results look like a Google SERP. A hit opens the live project when one exists, or this encyclopedia when it does not. A 23-second demo video of the search engine is hosted on the YouTube replica.
Background
The Replicates repository holds from-scratch copies of established software products.[1] Each replica folder carries its own README.md, SPEC.md, DECISIONS.md and research/ directory. The search engine was the first live deployment, in September 2026. Seven replicas are live (Linear, Notion, Super Smash, Fake Phone, Bet, FL Studio, and Dollar Pixels). Art Wall and Leaders are separate live apps, not replicas. YouTube still needs object storage, so its Website link stays a red stub. The interactive demos already run on the search site, so their Website links are live.
Replicas
Nine projects make up that half of the portfolio: an issue tracker, a workspace tool, a video platform, a fighting game, a personal-safety app, a prediction market, a pixel-grid homepage, a browser DAW, and a public drawing wall.
| Project | Replica of | Description | Tests |
|---|---|---|---|
| Linear | Linear | the issue tracker, rebuilt from measurements | 1,559 unit tests, 23 e2e |
| Notion | Notion | marketing site + product, one session | 147 tests |
| YouTube | YouTube | the server never opens a codec | 2,227 unit tests, 38 e2e specs |
| Super Smash | Super Smash Bros. Ultimate | eight fighters, one keyboard, sixty frames a second | 1,285 unit/property tests, 7 e2e |
| Fake Phone | the iOS and Android incoming-call screen | never feel alone | 363 unit tests, 89 e2e |
| Bet | Polymarket | a private, friend-first prediction market | ~664 unit/property/route tests |
| Dollar Pixels | The Million Dollar Homepage | $1 buys nine pixels | 414 unit/property tests, 30 e2e |
| FL Studio | FL Studio | the beat, not the DAW | 1,256 unit tests, 15 e2e |
| Island Empire | Island Empire | the Slay-like, on a square grid | 434 unit and property tests, 25 e2e |
| Risk | RISK: Global Domination | RISK: Global Domination, with the dice already in the action log | 1,880 unit and property tests, 18 e2e runs |
| Art Wall | r/place | a public chalkboard you can actually draw on | route and validation tests |
| Leaders | Sid Meier's Civilization V | Civilization from the ground, where orders travel by courier | 158 unit tests, 5 Playwright browser scenarios |
Interactive demos
Seventeen demos run inside David's Internet rather than on their own domains. They cover digital design, signals, TinyML, a hardware hackathon, EEG hardware, two Voytek Lab analyses, computer vision, a semantic graph of arXiv abstracts, cross-teaching segmentation, a P300 speller, SQL labs, early CAD, first programs, an agent memory trace, and a ROS 2 robocar.
| Demo | Origin | Description |
|---|---|---|
| Verilog | ECE 111 at UC San Diego | an 8-state Viterbi decoder you can watch think |
| Nocturnal Neuro | the OpenBCI Ganglion | from board to brainwave |
| Signals and Systems Lab | ECE 101 at UC San Diego | five ECE 101 labs, live in the browser |
| Quantum Playground | DTU course 10384, Quantum Information | the algorithms from DTU, running where you can see them |
| HardHack 2026 | HardHack at UC San Diego | a break-in detector from sensor to phone |
| ESP32 Thermal TinyML | ECE 140 at UC San Diego | from 64 pixels of heat to a 6,672-byte model |
| Organoids on Psychedelics | Voytek Lab at UC San Diego | a year of organoid electrophysiology, replayed as chapters |
| Anatomy of a Spike | Voytek Lab at UC San Diego | a primate action potential fitted live on public data |
| Computer Vision | CSE 152A at UC San Diego | classical vision, live: relight a face, click an epipolar line |
| arXiv Semantic Graph | DTU course 02807, Computational Tools for Data Science | 148k abstracts, one threshold, a graph you can drag |
| Cross-Teaching Segmentation | DTU course 02456, Deep Learning | a U-Net and a ViT swap pseudo-labels |
| P300 Speller | BCI Competition III dataset II | spell letters with an evoked potential |
| SQL Playground | DTU Databases course | five course databases live in the browser |
| Early 3D Modeling | Autodesk Inventor and VEXcode VR | Inventor CAD stories and VEX programs running in a 2D sim |
| Early Code | UC San Diego CSE 12, CSE 15L, and CSE 100 | the first C++ final, URL handlers, and Aho-Corasick from scratch |
| Agent Memory | Agent_Memory research repository | a governed memory trace, from evidence to cited context |
| Delta Cloud | Katalyxt AI | the AWS platform behind Katalyxt, drawn from its Terraform |
| Autonomous Car | ECE/MAE 148 Team 3 at UC San Diego | a ROS 2 robocar that follows tape and scoops up garbage |
Methodology
Each replica starts with parallel research lanes that gather facts about the real product, then a sequence of build slices that implement it. Lane and slice counts follow the project's scope. The YouTube replica used nine research lanes and twelve build slices, the Dollar Pixels replica used five of each, and Bet used a 14-task plan with an implementer, an independent reviewer, and a fix loop per task instead of the lane/slice split.
Independent review after implementation is the other recurring pattern. The Linear replica's three review rounds found 18, 20 and 7 issues, including a CSS url() injection vulnerability. The YouTube replica's five review rounds found roughly 72 findings in total.
See also
References
- ^ “Replicates.” Root
README.md.
- Portfolio indexes
- Software replicas
- 2026 establishments