Frontend Developer · Sono Solar GmbH
Remote (Munich, Germany)Jul 2024 – Aug 2026
- Frontend performance: Reduced the initial JavaScript bundle by 65% through code splitting, improving mobile LCP from 17.2 s to 8.9 s and Lighthouse Accessibility from 88 to 100.
- API performance: Reduced a production fleet-analytics endpoint from 6.91 s to 1.17 s by profiling the full request path and identifying Node-side time-series processing as the main bottleneck.
- Component development: Built and maintained ~25 reusable React/TypeScript components (forms, modals, tables, charts, map markers, loading and error states) against the team’s design system and Figma specs, reused across dashboard features and shared with the Installation Tool. Migrated CSS to Sass and adopted a layer-based frontend architecture.
- Multi-tenant authorization: Integrated a claims-based authorization model (OEM, fleet and user roles: viewer, admin, fleet admin) into a B2B React platform, controlling access to two products (Solar Analytics Dashboard, Installation Tool) and scoping data requests to each user’s fleet context.
- Authentication: Built an email one-time-code login flow end to end: React states for request, entry, invalid and expired codes, plus backend validation with single-use, time-limited codes, attempt limits and session creation.
- External data integration: Consumed Teltonika telematics data from BigQuery, handling delayed and incomplete payloads and distinguishing “no data” from “stale data”. Added bounded retries (temporary vs. permanent errors) and Slack alerting for missing telemetry and failed jobs. Integrated SendGrid for login codes.
- Dashboards and live map: Built fleet-analytics dashboards with Chart.js and a Mapbox vehicle map with periodic data refresh, isolating map state to avoid unnecessary re-renders.
- Backend, testing and CI/CD: Built and maintained Node.js, TypeORM and PostgreSQL functionality (data models, migrations, REST API routes, validation, Jest tests); wrote 30+ end-to-end flows with Magnitude AI (Playwright-based); worked with GitLab CI/CD and Docker for automated testing and quality checks.
- Product ownership: Ran user interviews and usage analysis for an installation workflow, identified distinct user needs, and built the frontend of a separate product now running on three OEM production lines. Used Claude Code, Codex and Cursor day to day, with manual review before release.
