Evidence — BI as Code (Open Source Contribution)
Upstream open-source contribution to evidence-dev/evidence (Svelte & TypeScript): architected the global multi-language system, language switcher UI, complete Italian localization, all-in-one MetricCard, interactive FilterPresets, and cross-filtering data configurations.
Overview & The Challenge
[Evidence](https://github.com/evidence-dev/evidence) is an open-source framework for building Business Intelligence reports as code using Markdown and SQL. As the platform expanded internationally, European enterprises and localized analytics teams required native multi-language support, automated UI translations, and more versatile metric summary components.
Architectural Additions
The contribution encompasses full-stack frontend architecture across the Evidence monorepo:
| Component | Technology | Impact |
|---|---|---|
| Multi-Language Engine | TypeScript & Svelte Stores | Reactive client-side locale switching with zero page reload latency. |
| Italian Localization | JSON Schema / i18n | Full translation of all error states, export tools, query inspectors, and UI labels. |
| MetricCard Component | Svelte 5 / Tailwind | Unified KPI component supportingsparklines, variance trends, and target comparisons. |
| FilterPresets | SQLGlot & Svelte | Persistent quick-filter dropdowns and cross-filtering synchronization across tabs. |
*Table 1: Key Architectural Additions in Evidence BI*
// Example: Reactive locale switching store in Evidence UI
import { writable, derived } from 'svelte/store';
import { translations } from './locales';export const currentLocale = writable('it'); export const t = derived(currentLocale, ($locale) => (key: string) => { return translations[$locale]?.[key] ?? translations['en']?.[key] ?? key; }); `
Results & Upstream Integration
- Seamless multi-language report generation for worldwide teams.
- Drastically reduced boilerplate when setting up localized KPI dashboards.
- Merged and maintained in upstream releases of Evidence.