Mario Kranjec

About

I’m Mario Kranjec, a senior backend engineer and contract tech lead based in Slovenia. I help small engineering teams build backends that hold up and keep shipping: as a fractional tech lead, through legacy migrations, performance work before big launches, and fixing slow delivery.

How I work

Slow delivery is rarely just a code problem. More often it’s unclear priorities, missing standards, or releases that are rare and risky. So I look at how your team plans, reviews and ships, not only at the code, and fix whatever slows you down most first. Good architecture matters, but it only pays off when your team can change it safely, every week.

Background

  • CargoX (2021–now): senior backend engineer on a blockchain platform for trade documents used by 180,000+ companies. Stood in as temporary acting team lead for seven engineers; introduced architecture standards, code-first API schemas, end-to-end testing with Playwright and a faster local setup.
  • InYourPocket (2024–2026, contract): tech lead for a team of four, migrating a 100+ city travel guide from Symfony to Next.js and NestJS. Read the case study.
  • Inova IT (2020–2021): senior backend engineer for a top global sportswear brand’s product-drop platform, up to 2.45M requests per second at peak. Read the case study.
  • LifeOnScreen (2017–2019): backend engineer on the APIs behind advertising-screen networks in the UAE, plus CI/CD and developer experience across four teams.
  • Before that: full-stack work on CRMs and integrations, and systems administration at a radio station.

I work mostly in TypeScript (Node.js, NestJS, Next.js), Python (Django) and PHP, with PostgreSQL, Redis, Kafka and Elasticsearch, on Docker, Kubernetes and AWS.

Community

Since 2018 I’ve co-organised Spletne urice Maribor, Slovenia’s longest-running tech meetup: more than 150 events over ten years. I also taught web development at the SmartNinja bootcamp.

Working together

I work remote-first in EU time zones, either fractionally (2–3 days a week) or on fixed-scope projects. See what I help with, or book an intro call.