Senior Engineer for Astronomical Engine Tool

Senior Fullstack Engineer — Astrology Web Tool, Backend Computation + Dashboard Build

Project

Web-based consumer astrology tool needs senior fullstack engineering to complete the backend computational layer, build the configuration system, and ship the production dashboard. The computation provider (Swiss Ephemeris) is licensed and integrated. The work is finishing what's incomplete, validating output to reference data, building the configuration system and UI, and shipping the dashboard.

Stack (existing)

- React 19 + TypeScript, TanStack Router, Zustand, Tailwind v4, Vite
- Supabase backend (Postgres + Deno edge functions, Lovable-Cloud managed)
- Project lives in Lovable. Contractor may work inside Lovable directly OR sync via GitHub for local IDE work.

Budget

$10,000 to $20,000 USD total across six fixed-price milestones. Fixed-price per milestone only. Payment releases on milestone acceptance.

Six Milestones

Each milestone has a defined deliverable and a written acceptance test. Off-ramp available after any completed milestone.

**M1 — Diagnostic audit, calculation bug fix, test scaffolding.**
Diagnose and fix the calculation non-determinism bug (same birth data currently produces inconsistent positions). Written audit of the existing computational layer. Test infrastructure scaffolded with 10 reference birth-data cases passing.

**M2 — Planetary positions and lunar nodes.**
All planetary positions Sun through Pluto, true and mean lunar nodes, retrograde flags, declinations, distances. Tropical and sidereal zodiac options. Validation suite expanded to 30-40 test cases against established reference data.

**M3 — House systems.**
Placidus, Koch, Whole Sign, Equal, Porphyry, Regiomontanus. Ascendant and Midheaven validated separately. House cusps validated to reference precision.

**M4 — Aspects and configuration data model.**
All major and minor aspects with configurable orbs. User configuration data model (default house system, zodiac, ayanamsa, orbs, default chart preferences), persisted per user with per-chart overrides. Computational architecture documentation.

**M5 — Configuration UI and dashboard scaffolding.**
Settings panel for configuration management. Dashboard layout and widget framework. Tier-aware section rendering.

**M6 — Natal wheel, tables, final acceptance .**
SVG natal chart wheel (Whole Sign default with switchable house systems, MC/IC markers, AC at 9 o'clock left, counter-clockwise numbering, responsive, accessible, PDF/PNG export). Three tabbed tables (Positions, House Cusps, Aspects). Final UI acceptance checklist (approximately 30-40 cases) signed off.

Required

- **Minimum of 8+ years senior fullstack experience.** Production React/TypeScript on the frontend AND production backend (Node.js, Deno, Python, or comparable) within the last 18 months.
- **Demonstrated astronomical software experience.** Shipped production code consuming Swiss Ephemeris, NASA JPL Horizons, NAIF SPICE, NOVAS, or comparable. Repos, papers, or shipped products.
- **Validation suite discipline.** Recent repo where you wrote computational test suites against reference data.

Nice to have

- Prior astrology software company experience (TimePassages, AstroGold, Solar Fire, AstroSeek, Astrodienst, Kerykeion ecosystem)
- Lovable platform familiarity
- Timezone-handling depth (Luxon, date-fns-tz, IANA tz database)

Process

1. Bid per "How to Bid" below.
2. First call (45 minutes) under mutual NDA. NDA sent when call is scheduled.
3. Independent Contractor Agreement signed: full work-product IP assignment, milestone-based escrow payments, off-ramp after any completed milestone.
4. Codebase access after agreement signs.
5. Async-first communication, weekly sync. Founder works in US Mountain timezone.

How to Bid

1. **Senior fullstack experience.** One project from the last 18 months: name, your role, what you shipped.
2. **Astronomical software portfolio.** URL plus one-sentence description of your specific contribution. **Required.**
3. **Validation approach.** One paragraph: reference data you trust, your test strategy.
4. **Bid structure.** Fixed-price per milestone (six numbers plus total). Either all six together OR M1 only with ranges for M2-M6.
5. **Architecture preference.** One paragraph: vendor Swiss Ephemeris C library directly, continue WASM wrapper, separate Python compute service, or other approach. Why.
6. **Delivery date per milestone** from contract signature. Your time zone.

Global bidders welcome. Fastest delivery preferred. Bids without astronomical software portfolio links will be skipped.**