Building enterprise-grade backend systems for ERP, invoicing, and automation across 5 Balkan markets.
Currently Head of Software Development @ Elastyc Net (Belgrade).
A selection of production systems built for enterprise automation, document workflows, and data pipelines.
Automated XML e‑invoice generation, validation, and SEF API submission.
Handles over 20K invoices monthly with less than 1% error rate.
Highlights
- Outbound invoice management (send individually or in bulk)
- Real‑time status tracking and filtering
- Inbound invoice management with approve/reject workflows
- XML/PDF attachments and full SEF synchronization
- Automated retrieval of unseen invoices directly from SEF API
Tech Stack: PHP 8 · Guzzle 7 · XML / UBL 2.1 · JSON Logging · SQL Server / SQLite
UI Screenshots
| Outbound Invoices | Outbound Invoice Details |
|---|---|
| Inbound Invoices | Inbound Invoice Details |
|---|---|
High-throughput reindexing and data ingestion system for Elasticsearch 7.17.x and SQL Server 2019+.
Handles millions of rows per job with zero downtime, background workers, and idempotent upserts viaacckey.
Highlights
- 🚀 Background workers — long jobs run outside HTTP, safe from Cloudflare limits
- 🧩 Batching with ROW_NUMBER() / OFFSET — handles multi-million-row tables
- 🔁 Idempotent upserts — every document uses acckey as Elasticsearch _id
- 💾 Job queue — file or SQL Server-based persistence
- ⚖️ Retry logic + dead-letter queue for bad docs
- 🧹 Normalization of dates, nulls, and diacritics
- 📊 JSON logging for dashboards and traceability
Dashboards & KPIs
| Fleet Dashboard | Sales KPI Dashboard |
|---|---|
Elasticsearch Tables
| Modules Reindex Table | Global Reindex Table |
|---|---|
Advanced DocuSign automation platform integrating OAuth2, envelope queuing, and secure webhooks.
Enabled same‑day digital contract completion and background‑safe processing for large-scale deployments.
Highlights
- Full OAuth2 flow (authorization code with PKCE support)
- Background envelope worker with retry and dead‑letter handling
- Secure webhook validation (HMAC SHA‑256)
- Supports file and SQLite job stores
- Designed for production DocuSign environments
Tech Stack: PHP 8 · DocuSign SDK 6.x · Guzzle · SQLite / File Queue · REST API · JSON Logging
Languages / Frameworks: PHP 8 · SQL Server · Elasticsearch · jQuery · AJAX
APIs & Integrations: SEF API · DocuSign · Pantheon ERP · Postmark · TecAlliance · OpenAI · Google
DevOps: GitHub Actions
Tools: Postman · Git · Tabulator.js · XML processing
(Expanding into Python/FastAPI & cloud data pipelines.)
Backend engineer specializing in enterprise automation and ERP integrations.
Experienced in leading small backend teams, designing scalable data pipelines, and optimizing search infrastructure.
Passionate about reliability, clean architecture, and automating the boring stuff.
📍 Belgrade, Serbia (UTC+1)
📧 [email protected]
🔗 LinkedIn