Іван

Ivan Khamar
Software Developer · ERP & Business Systems · PHP, SQL, .NET, Integrations
Lviv, Ukraine (hybrid or remote) · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) ·
[open contact info](look above in the "contact info" section)
SUMMARY
Developer with ~3 years on a manufacturer's CRM: first in operations and logistics, then as its sole developer. I take
tasks from business request to production. Also C#/.NET, BPMN, and Python; AI-assisted development (Claude Code,
Gemini) daily. PhD candidate in Computer Science.
EXPERIENCE
Vidro.ua — apparel and art brand with in-house production, Lviv · Jan 2024 – Oct 2026
Software Developer · Jun 2025 – Oct 2026
Sole developer: website (OpenCart/PHP), CRM/admin panel, integrations, and analytics.
Business processes and integrations
Inventory and production module: materials (33 suppliers, ~60 items), sewing stages, stock sync with the catalog.
BOM-based material write-off on order status change; idempotent, cancel-reversed.
Shipping safeguards for staff: server-side checks, status history, single-order mode.
Nova Post International API: JWT auth, OpenAPI spec, customs codes, cancellation.
Faster Nova Poshta waybills (was ~20 s): sender data from the DB, retry with backoff.
Partner XML feeds with EAN-13 barcodes, accepted by EVA; Checkbox, SMS, Klaviyo.
Data and security
MySQL DB from over 2 GB to ~240 MB: removed ~2.6M expired sessions and obsolete data.
Sales report scanning 717K rows (~3 min): fixed a wrong JOIN via EXPLAIN, added indexes.
GA4 attribution via Measurement Protocol and BigQuery: "Unassigned" 14% → 0.15% of sessions.
Checkout bot protection (Cloudflare, honeypots); mitigated a DDoS attack.
Process: ~200 Kanban tasks in 6 months, BPMN, Claude rolled out to the team.
Shipping & Logistics Specialist · Jan 2025 – Jun 2025
Shipments, waybills, returns, and fiscal receipts in the CRM; later automated as a dev.
Operations Specialist · Jan 2024 – Dec 2024
OpenCart admin (products, content, orders); SQL queries on product popularity and sales.
PROJECTS
NewErp · Oct 2026 · github.com/IvanKhamar/NewErp
ERP in C#/.NET 10 that replaces the accounting part of a legacy OpenCart store module by module, on the same
MySQL schema. Built with Claude Code.
Clean Architecture (Domain, Application, Infrastructure, API), enforced by a layer dependency test.
Orders with status audit log, manager bonuses, inventory with movement journal; ASP.NET Core Minimal API,
ProblemDetails, OpenAPI/Scalar.
EF Core database-first on legacy tables, optimistic concurrency on stock; xUnit unit and MySQL integration tests.
SKILLS
Main stack: PHP (OpenCart, MVC), MySQL/SQL, REST APIs, JavaScript, HTML/CSS
Also: C#/.NET 10 (ASP.NET Core, EF Core, LINQ, xUnit), Python, BPMN 2.0
Infrastructure and analytics: Linux/SSH, Cloudflare, Git, GA4, BigQuery
AI tools: Claude Code, Claude, Gemini
EDUCATION
PhD candidate, Computer Science (122/F3) — Ivan Franko National University of Lviv, 2024 – present. Research:
ML for real-time streaming data. Department assistant, 2024–2026.
Master's, Software Engineering (121/F2) — Lviv Polytechnic, 2022–2024.
Bachelor's, Software Engineering (121/F2) — Lviv Polytechnic, 2019–2022.
Publications: 4 papers in scientific journals and proceedings (2024–2026) · ORCID 0009-0000-0514-903X
Languages: Ukrainian (native), English (B2, upper-intermediate)