G-vL Home — A Family Operating System

CASE STUDY

How this was built

One developer. Three workspaces. 53 hours.

530

SUB-AGENTS LAUNCHED

53h

HUMAN TIME

58h

AI TIME

60 000+

LINES OF CODE

378+

TESTS

EN, DE, PL, HU

LANGUAGES

WORKSPACES

111

PARALLEL WAVES

Activity Timeline: 3 Workspaces, 17 Days

home-app homelab private-ecosystem

02 05 08 11 14 17 20 23

Mar 3

Mar 4

Mar 10

Mar 11

Mar 12

Mar 13

Mar 14

Mar 15

Mar 16

Mar 17

Mar 18

Mar 19

Mar 20

Mar 21

Mar 22

Mar 23

Mar 24

Traditional Build

Line Item	Hours	Rate	Cost
Research & Discovery	100	blended	€11 500
Rust Developer	375	€125/h	€46 900
Android Developer	280	€115/h	€32 200
Frontend Developer	165	€105/h	€17 300
DevOps Engineer	140	€115/h	€16 100
PM / Architect	70	€125/h	€8 750

Total

€132 750

1 130h · 14 weeks · 5 people

AI-Augmented Build

Line Item	Hours	Rate	Cost
Widgets & Features (13)	20	€120/h	€2 400
Infrastructure (Auth + Caddy + CI/CD)	18	€120/h	€2 160
Android App (zero prior exp.)	5	€120/h	€600
Onboarding Wizard	4.5	€120/h	€540
StataBar + StataAPI	4	€120/h	€480
Architecture & Planning	1.75	€120/h	€210

Total

€6 390

53h · 1 person

All rates based on 2026 Western European freelancer market.

Read the full case study →

MODULES

Nine data feeds. One host.

Each plugin fetches, caches, and serves one data source. The host handles failover.

DWD

Wetter

/weather

DWD open data. 240-hour forecast with Canvas weathergraph. Temperature gradient line, precipitation, night bands, gust markers, condition icons. Nowcast radar sparkline. 7 condition categories.

Temp11°C gef. 8°

Wind9 km/h SW

Chart10-day weathergraph

BVG

Nahverkehr

/transit

Real-time BVG departures for nearby stops. Geolocation-aware with colored line badges.

U7 Spandau3m

U8 Wittenau5m

M41 Südkreuz14m

BSR

Abholung

/garbage

BSR pickup schedule with waste type colors and urgency indicators. 6h cache.

Biogutmorgen

RestabfallMo 17.

WertstoffeDo 20.

Wechselkurse

/exchange

Exchange rates via ECB (European Central Bank). EUR and CAD base pairs. Dual-currency view for family across countries.

EUR/USD1.0834

EUR/GBP0.8621

EUR/CAD1.4832

Feiertage

/holidays

German public holidays from Nager.Date merged with family birthdays. Regional filtering for Berlin. 24h cache.

Karfreitagin 13 Tagen

Ostermontagin 16 Tagen

🎂 Claudiain 31 Tagen

Portfolio

/portfolio

Ghostfolio integration. Per-user access tokens, each user sees their own portfolio. 5m cache.

Total€12,340.18

Today▲ 2.31%

Absolute+€278.41

Baby

/baby

Baby Buddy integration with circadian-aware predictions. Gaussian probability curves for next feed, sleep, diaper. Quick-log with undo. Analytics timeline on Glance widgets.

Flasche170ml · vor 47m

Schlafseit 2h 10m

Vorhersage~14:30 Flasche

Zeitzonen

/timezones

World clock with overlap planner. Computed per-request, no upstream API, no cache.

Berlin15:14 ●

New York09:14 ●

Overlap15–17 Uhr (2h)

NETWORK

18 services. One network. Zero cloud.

Mesh VPN

CONNECTIVITY

All devices on the same Tailnet. Internal traffic resolves via *.example.net MagicDNS. Traffic never leaves the mesh.

Single Sign-On

IDENTITY

One login for every service. OIDC identity provider with Caddy handling auth across all *.example.net subdomains. Per-user, config-driven feature access.

The ecosystem

Every service behind *.example.net. Single sign-on. One Tailnet.

■ public + VPN ■ VPN-only

Office Suite

Cloud storage, file sharing, and document collaboration for the family.

Photo Library

Self-hosted photo and video backup with face recognition and map view.

Book Library

E-book catalog and reader with metadata management.

Recipe Collection

Family recipes with meal planning, shopping lists, and ingredient scaling.

AI Chat

Private LLM interface with model switching and conversation history.

Voice Synthesis

Voice clone text-to-speech for custom audio generation.

Document Archive

OCR-indexed document management with tagging and full-text search.

Password Vault

Family password manager with browser extension and mobile apps.

Backup Manager

Deduplicated, encrypted backups with retention policies and restore UI.

Family Onboarding

Invite-based enrollment wizard with QR codes for new family members and devices.

DASHBOARD

Full-page dashboard, same bundle, different mode.

The StataBar JS bundle doubles as a full-page dashboard at dashboard.example.net. Service launcher with generative tile art, live data widgets, quick-log actions. Same code, data-mode="dashboard".

SERVICE LAUNCHER : GENERATIVE TILE ART

LIVE DATA WIDGETS : BELOW THE FOLD

G-vL Dashboard widget cards with live data

SIDEBAR

StataBar, injected into every service.

A single JS bundle injected via Caddy replace-response into every *.example.net site. Closed Shadow DOM. Zero runtime dependencies. Icon rail on top, Ctrl+K expands the full panel with live data, service navigation, and quick actions.

ICON RAIL : OVERLAID ON PROXMOX

EXPANDED PANEL : CTRL+K

StataBar expanded panel with weathergraph and transit

SYSTEMS

Four systems. One data flow.

StataAPI

Rust · Axum · Tokio

Plugin host with circuit breaker and cache warming. Fetches 9 upstream APIs, caches with TTL, serves a unified JSON contract. Baby analytics with circadian prediction engine. Stale fallback on failure.

StataBar

TypeScript · Shadow DOM · esbuild

Injected into every proxied service via Caddy replace-response. Closed Shadow DOM. Zero npm runtime dependencies. Dashboard mode, sidebar mode, admin panel. Same bundle, different modes.

StataApp

Kotlin · Compose · Glance

Android app with 7 homescreen widgets. QR enrollment. Size-adaptive Glance layouts from 2×1 through 4×2. Canvas-rendered weathergraph and baby prediction timelines. Self-hosted F-Droid deploy.

gvl-onboard

Rust · Axum · Tera

5-step family enrollment wizard. Tailscale VPN provisioning, F-Droid setup, Zitadel account creation, service tour. Invite-based with live connectivity checks. 4-language support.

Upstream APIs

→

StataAPI

→

StataBar

StataApp

PROCESS

Spec-driven agentic development.

Not vibe coding. Architecture decisions first, implementation second. Claude handles the breadth while the human steers the depth.

Specs before code

35 markdown specification documents written and interrogated before a single line of code. API contracts, auth flows, cache strategies, widget layouts, all decided up front.

Plugin architecture from day 1

A DataPlugin trait defines the contract. Each feature implements it. The host owns HTTP, caching, and circuit breaking. Plugins are passive: they declare, they don't orchestrate.

Verify before every commit

One script runs fmt, clippy, test, and build across all three systems. Nothing ships without green across Rust, TypeScript, and Kotlin simultaneously.

Sub-agent delegation

Opus handles architecture and cross-system decisions. Sonnet sub-agents handle implementation, test output interpretation, and file exploration. Cost hierarchy respected.

stataapi/src/plugin.rs : THE ONLY TRAIT

/// Every feature implements this. /// The host does everything else. pub trait DataPlugin: Send + Sync { fn name(&self) -> &str; fn prefix(&self) -> &str; fn routes(&self, state: AppState) -> Router; } // AppState is hand-rolled DI: pub struct AppState { pub cache: TtlCache, // DashMap-backed pub client: reqwest::Client, // shared pub config: Arc<AppConfig>, } // 27 plugins. One trait. No macros. // 21 000 lines of Rust across API plugins alone. // // feature api web ui app // weather 1 991 849 742 // baby 1 354 1 624 1 381 // portfolio 1 806 542 958 // transit 1 461 400 693 // timezones 960 321 848 // holidays 707 360 542 // exchange 808 289 - // garbage 656 304 654 // postal 419 321 - // office 413 299 - // system health 642 321 -

Vendor

The vendor of this internet presence is in the legal sense:

Building Better Teams - Brian Graham
Mühlenstraße 8a
14167 Berlin, Germany

Contact

USt-ID: DE354152177
brian@buildingbetterteams.de
+491783212891

Interstate Broadcasting Agreement

Responsible for content within the meaning of section 55 (2) RStV (Rundfunkstaatsvertrag): Brian Graham

Representative

Building Better Teams is legally represented by Brian Graham

Legal Structure

"Building Better Teams - Brian Graham" is an independent consulting practice from Brian Graham, serving technology companies since 2022, registered (Gewerbeanmeldung) as a sole proprietorship (Einzelunternehmer) at the district office (Bezirksamt) Steglitz-Zehlendorf, Berlin, Germany. Registration with HRB has not been required for this sole proprietorship.

G-VL
HOME

How this was built