FRAME 01 · ABITURCompleted 2021
Abitur.
Gymnasium
School
Dietrich-Bonhoeffer-Gymnasium
Place
Schweich
Advanced courses
English · Math · Physics
DEV 000%01/04
AF · SEEKING
Web & AI Developer
Trier · 2026
Joël
Deffner.
CS master’s student in Trier. The last frame off the roll: a Quest 3 that finds the cables inside a real wall.
On this page
01Education↓02Skills & About↓03Selected work↓04Photography↓Just the facts?
Open full CV →
Open full CV →
INDEX · 04 SECTIONS
23mm · f/2 · ISO400@joel.intheskies
Scroll · start with the studies ↓Frame 00 / 04X100V · 23mm · f/2 · ISO400
01 — Education
The studies.
From an Abitur in Schweich to a master’s at Trier. Frame four is still unexposed.
FRAME 02 · B.SCCompleted 2026
B.Sc.
Computer Science
Institution
Universität Trier
Graduated
2026
Minor
Japanese
DEV 000%02/04
FRAME 03 · M.SCIn progress
M.Sc.
Computer Science
Institution
Universität Trier
Expected
2028
Programme
120 LP under FPO 2020
DEV 000%03/04
FRAME 04 · UNEXPOSEDOpen
You?
The next frame
Your company name here
Reserved for a working-student role, or the first job after the M.Sc. The reel has room.
Get in touch →DEV 000%04/04
02 — Skills & About
Behind the lens.
Less hype, more “does this actually work?”
I pick up new AI tooling the week it ships and keep whatever survives contact with a real project. This site is the test bench: agents do a lot of the typing, I do the judging. Which is why the contact sheet grades nothing about me. Every frame says what you can check: source you can open, a result you can look at, or my word and nothing behind it. I’m an entry-level engineer, and that third tier is on the sheet because leaving it off would have been the dishonest part.
DEUTSCHNATIVE
ENGLISHFLUENT
日本語 · JAPANESEUNICERT® BASIS
The contact sheetExposure = what you can check
Code you can readResult you can seeTake my word
Sheet 01 · 23 framesUncropped
TypeScriptCODE YOU CAN READ
Four codebases: the CK3 toolkit's language server (721 tests across 59 files), ai-form-fill on npm, a rules engine shared unchanged by a socket server and a React client, and this page. The toolkit is GPL-3.0 and public, so don't take my word for the test count. Go and run it.
HoverTap a frame to read its caption
03 — Selected work
Selected work.
Seven frames, newest first, each with its development notes on the back.
Frame 01 · 2026 · Master's research projectPaused since July
Speak a scene into VR
You describe a scene out loud and an agent edits a persistent VR world turn by turn instead of regenerating it. Nine scene operations and two session operations, one Anthropic tool each behind a strict JSON schema, carried over a WebSocket between a Python FastAPI service and Unity. The P0 scaffold runs end to end against a deterministic fake LLM, so routine tests never make a paid API call. Two-person thesis, 14 weeks, Trier.
UnityQuest 3FastAPIAnthropic tool use
Development notesAI Some · on the wiring
- AI
- The wiring and the Meta XR audit after the scaffold landed.
- Me
- I wrote the P0 scaffold myself in one session, 49 files, and the twelve architecture decisions under it: Unity validates every layout the agent proposes and can reject it, and MCP never ships in the runtime.
Voice → scene · Quest 3
MIC“a pine forest at dusk, with a campfire”
PERSISTENT · EDITABLEAGENT LISTENING…
UNITY · FASTAPI · WEBSOCKETFRAME 01
AR reveal · real wall
Press and hold
REVEAL r = 25 CM · HAPTIC 0.12 SIN RANGE 0 / 5
UNITY 6 · META XR · MRUKFRAME 02
Frame 02 · 2026 · Quest 3 · Shipped July 2026
Seeing Through Walls
You want to drill into a wall and you need to know what is behind it. In AR the app reveals the cables, studs and pipes inside the real wall within 25 cm of your hand; in VR you grab a copy of that same wall, scale it up and place the holes precisely; then the plan goes back onto the real surface. Manipulating the copy moves its root transform and never the data, so a pin placed on a wall blown up to twice its size still lands on the right millimetre of the real one. The structures are generated, not detected: only the sensor reading is simulated, and everything around it is real.
Unity 6Meta XR SDKMRUKPassthroughC#
Development notesAI High · on the typing
- AI
- All 10 runtime C# scripts, both editor tools, and the procedural cable and stud generation.
- Me
- Keying every plan to the wall's anchor UUID was my call, and so was killing the ArUco path once each iteration cost a 20-minute build. The ordering bug was mine to find on the headset: SetWall cleared the model, the clear fired a save, the empty plan cached, generation skipped.
Frame 03 · 2026 · VS Code extension · GPL-3.0
CK3 Modding Toolkit
A VS Code extension and standalone language server for Paradox script. It derives every piece of its language knowledge from the game install and the game's own logs instead of hard-coding it, so a new DLC or patch never needs a data release from me. Deep validation goes to ck3-tiger rather than being reimplemented: annotate, never hide. 721 tests across 59 files. Public on the Marketplace since July 2026, currently v0.1.x.
TypeScriptLanguage serverGUI previewck3-tiger
Test strip · measured before and after
Top-5 completion accuracy23.5%→33.8%
Replaying real typing through VS Code’s own fuzzy-match scorer is what moved these. Corpus: about 6,000 real mod files; unknown scope over 807,000 trigger and effect sites.
Development notesAI High · on the typing
- AI
- Most of the TypeScript, and every measurement harness behind the strip above.
- Me
- I install each build and use it on my own mod. A gap I report becomes a permanent script in scripts/, never a one-off fix, and rank quality gets measured before and after every ranking change.
TS · LSP · VS CODEFRAME 03
REACT 19 · CI4 · MYSQLFRAME 04
Frame 04 · 2026 · Team project · MIT
FlightMeet
A community platform for paraglider pilots: find and join local flying meets, coordinate in groups, chat, and check the weather at the launch site. React 19 in front of a CodeIgniter 4 JSON API, about 30 endpoints behind one error contract. Wind is first class throughout, speed and gusts and direction and daily maxima, because wind is what decides whether a pilot flies. Chat polls every 3 s for anything newer than the last message id, since the university host cannot serve websockets.
React 19TypeScriptCodeIgniter 4MySQLOpen-Meteo
Development notesAI High · on the typing
- AI
- Backend and frontend were written concurrently by separate agent workstreams.
- Me
- That only worked because I froze the API contract in writing first. The rules are mine: CodeIgniter never renders HTML, every network call goes through one lib/api.ts, counts are derived at read time.
Frame 05 · 2026 · Bachelor thesis · MIT
ai-form-fill
A zero-dependency TypeScript library that fills any HTML form from unstructured text or speech. It derives a JSON schema from the DOM, the exact option values included as enums, then hands that schema to the model, so the contract comes from the form and never from a config. Framework-agnostic through ids and data attributes, MIT, ESM and UMD, and 132 unit tests that map one to one onto the thesis' functional requirements. Local Ollama or any OpenAI-compatible endpoint.
TypeScriptDOMLLMSchema-first
Development notesAI Some · on the rework
- AI
- The July rework commits. The thesis and its requirements-to-tests mapping are my own academic work.
- Me
- I found three of my own claims false. Framework-agnostic was silently broken for React: element.value does not update a controlled component. The fix, a native prototype setter plus synthetic events, carries the whole library.
TS · ESM + UMD · LLMFRAME 05
Board · Drag & drop
TODO
DOING
DONE
ROLES: ADMIN · USER · GUESTMOVING…
CI4 · MYSQL · JSFRAME 06
Frame 06 · 2024 · Team project · Full-stack
Kanban board
A full-stack web app from the Web Development course: CRUD through modals, drag and drop between columns, and role-based access for admins, users and guests. CodeIgniter, MySQL and plain JavaScript, built by the team in the year I was tutoring the same course.
PHPCodeIgniterMySQLJavaScript
Development notesAI None
- AI
- None. 2024, and it predates all of this.
- Me
- Typed by hand, as coursework, alongside tutoring the course it came from.
Frame 07 · 2023 · Team of 4 · VR
GazeFactory
A Unity/C# gaze-guiding system that leads a user through a safety-critical simulation. A state model detects operating errors and steers the gaze, through a full 360°, to the next correct step. My first Unity project, and the start of the line that frames 01 and 02 sit on.
UnityC#VRGaze guiding
Development notesAI None
- AI
- None. 2023, before any of this existed.
- Me
- One of four on the team. It is on the page for the trajectory, not for the code.
Gaze guiding · 360°
ERROR-STATE MODELSTATE: SEEKING
UNITY · C# · 360°FRAME 07
Off the syllabus
Teaching & involvement.
Prints from the hours that never show up on a transcript.
Universität Trier2024
Web dev tutor
Ran exercise groups for the Web Development course: debugging student PHP, giving feedback on submissions, and explaining CodeIgniter’s router until it stuck.
PHPCodeIgniterJavaScriptLed 1 session solo
PRINT A · TEACHINGFIX · WASH · DRY
Universität Trier2023 – NOW
Student government
Three elected mandates since 2023. Less politics than it sounds: mostly agendas, minutes, and defending the student angle in faculty meetings.
Fachschaftsrat2023 – now
Fachbereichsrat2025/26 term
StuPa2025 – now
Test strip · pick a year3/4 exposed
In 2026 · 3 of 4
Fachschaftsrat · Fachbereichsrat · StuPa
PRINT B · COMMITTEE3 BODIES · 3 YEARS
Old-school photography roots
I learned to see before I learned to code.
Fujifilm X100V · 23 mm · deliberate frames
Turn the ring until the patch coincides
0.711.535∞
MF · 23 MM · f/2
FOCUS 000%
▢ Frame 04● EVF · X100V 23mm
04 — Photography · @joel.intheskies
The other portfolio.
Travel, light, and the quiet in between, all through one fixed lens.
Trafalgar Square, LondonX100V · 23mm f/2 fixedFlick the lever for the electronic finderThe meter reads whatever you point at
Last frame
Get in touch.
No contact form, no scheduling link. Mail gets read, usually between a Quest 3 build and an exam.
Paper · unexposed0.0 s
The print
One sheet, one frame. Hold the button to keep the enlarger on, let go when it looks right. The paper does not give any of it back.
Metered · 2.2 to 3.4 s5.5 s max
JD.
© 2026 JOËL DEFFNER