// sergiuscraft.com — Mykolayiv, Ukraine 🇺🇦
Full-stack developer specialising in finance integrations, EDI pipelines, and backend automation. Python, Perl, PHP, vanilla JS. Code that ships clean and runs quietly.
// expertise
Production experience with UBL 2.1, OIOUBL, SVEFAKTURA, SAF-T PL, EDICOM, and Sendys. Built parsers, validators, and delivery pipelines for EU e-invoicing mandates across multiple countries. PEPPOL-aware, format-fluent.
Designed and built end-to-end dunning email systems — escalation logic, template engines, scheduling, and audit trails. Finance-domain thinking baked in from day one, not bolted on after.
High-throughput pipelines, cron-driven processors, SFTP/OAuth integrations — the unglamorous infrastructure that keeps financial systems running at scale. Fault-tolerant, zero drama.
Full-stack PHP/MySQL with vanilla JS frontend. No framework religion — just clean, maintainable code that renders fast and doesn't require a build system to change a button label.
MSc in Enterprise Financial Controlling + years in financial services. I understand the business logic behind the code — AR, AP, audit trails, reporting, and compliance aren't just requirements, they're context.
Linux-first developer. Arch + macOS daily. SVN, Git, custom deploy scripts, monitoring hooks. Comfortable owning the full stack from OS up — not just handing off to someone else's pipeline.
// experience
// selected work
Multi-format e-invoice generation and delivery across UBL, OIOUBL, SVEFAKTURA, SAF-T PL, EDICOM, and Sendys. Handles country-specific validation, retry logic, and audit logging.
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A-02Automated accounts receivable dunning — escalation sequences, dynamic templates, scheduling, and full audit trail. Reduced manual AR workload significantly.
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Secure data exchange layer connecting internal systems with external finance partners via OAuth 2.0 and SFTP. Handles token refresh, retry queues, and delivery confirmation.
Internal reporting dashboard and audit summary tooling for a UK financial services company. Aggregates transactional data, generates period reports, and maintains a tamper-evident audit trail. PHP + MySQL + vanilla JS — zero framework dependencies, runs fast on modest hardware.
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// about
Code as craft. Finance as context. No overengineering, no framework soup.
I'm Sergius — a developer based in Mykolayiv, Ukraine 🇺🇦, with 7+ years shipping production code in financial services. My background is unusual: an MSc in Enterprise Financial Controlling landed me in tech, so I actually understand the business logic behind the systems I build.
My main arena is backend — Perl, Python, PHP — with a heavy focus on finance integrations: EDI formats, dunning pipelines, OAuth handshakes, SFTP transfers. The kind of plumbing that has to work silently at 4am.
Environment: Arch Linux + macOS. Vanilla JS because the web already works. Available for remote contracts. Fast to reply. Slow to ship bugs.
// contact
Open to remote contracts, consulting, and interesting problems. Fast response guaranteed.