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BackendDecember 2025
Maxis E-Invoice

Overview
Maintained and enhanced the Maxis E-Invoice back-end for scalability. Engineered a PDF worker generating 7.5M PDFs in 30 days, cutting BigQuery calls by 90%. Designed a cancellation system handling 36K invoices in 2 days. Automated scheduled PDF generation and invoice table submissions.
Key Achievements
- 1Maintained and enhanced the Maxis E-Invoice back-end for scalability and high performance.
- 2Engineered a PDF worker generating 20M PDFs in 30 days, cutting BigQuery calls by 90% and improving speed by 60% with batch processing.
- 3Designed a cancellation system handling 36K invoices in 2 days under IRBM 12 RPM with 90% success.
- 4Automated scheduled PDF generation of 500 PDFs in approx. 3 minutes, batching every 30s for optimized throughput.
- 5Delivered a document search feature, reducing retrieval time and improving accessibility.
- 6Automated invoice table submissions, streamlining workflow and reducing manual effort.
- 7Added a duplicate submission prevention mechanism for IRBM, improving reliability.
- 8Integrated XML submissions with webhooks for real-time updates and seamless SAP tracking.
- 9Implemented TIN validation to ensure compliance and data accuracy.
- 10Supported invoice cancellation, credit notes, and self-billed credit notes.
- 11Created reconciliation workflows with CSV files from GCP buckets to resolve inconsistencies.
- 12Converted documents into UBL 2.1 format for standardized e-invoicing.
- 13Built a data pipeline with a webhook listener, storing PDF status in BigQuery for analytics.
- 14Added QR code generation for invoices and merged it into HTML-based PDF templates.