Convert existing Python data-scraping script into online system (Google Sheets + FastAPI + job queue, exact output match)

I need an experienced Python backend developer to convert my existing, fully working Windows-based Python script into a fully online, scalable system, while preserving 100% of existing features, outputs, and logs.

The current script already:

Collects and processes structured data
Generates XLSX, HTML, RSS
Generates OPML (.xml) for RSS/feed readers
This is a refactor/orchestration project, NOT a rewrite.
Final outputs must be identical to the offline version.

Non-negotiables (read carefully)
❌ No feature removal
❌ No output or behavior changes
❌ No logic rewrite
✅ Exact output parity required
✅ Existing logs must remain (or improve)
If you plan to simplify, rewrite, or change behavior, do not apply.

>> Required architecture (must follow)
Google Sheets (control panel)
→ FastAPI backend
→ Database
→ Redis + Celery/RQ (job queue)
→ Worker processes (reuse existing logic)
→ Outputs (RSS, OPML, XLSX, HTML, logs)
Google Sheets = input/control only
Job queue + workers are mandatory
Running multiple script copies is NOT allowed


>> Core requirements
Manage queries/tasks via a single Google Sheet

Add / remove / enable / disable
Per-task scheduling + stop rules (date or run count)

Global pause / resume (respect disabled tasks)

Concurrent execution via workers

OPML per group (tasks don’t need removal if later inactive, can be kept, but new tasks keep adding to the OPML group)

Logging (very important)
Full log files must remain (same detail or better)

Logs must auto-rotate

Live log view required (last ~1000 entries) via:

FastAPI / Redis / DB, or
Separate Google Sheet, or
Another reliable method
Payment terms (strict)
❌ No milestone payments
❌ No partial payments
✅ One-time payment only after full completion, testing, and approval
Apply only if you agree.

>> Intellectual property (mandatory)
All code and outputs are my exclusive property
Work is work-for-hire
No reuse, resale, or publication (including portfolio/GitHub)
All materials are confidential

>> What I provide
Existing offline Python script
Sample inputs & outputs (RSS, OPML, XLSX, HTML)
Google Sheets access

>> To apply, answer briefly
How will you ensure no feature or log is lost?
How will you guarantee exact output parity?
Experience with FastAPI + job queues?
Applications without answers will be ignored.

Budget
Fixed price, paid once after completion and final approval.