Hi, I'm Ivan

Senior
Full Stack
Engineer

I build reliable, scalable enterprise software for telecom, railway and SaaS — specialised in Java/Spring Boot backends, Vue.js frontends and cloud infrastructure across AWS, GCP and Azure.

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Professional & Reliable
Fast & Efficient
Clean & Maintainable Code
Ivan Landeka - Senior Full Stack Engineer
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Available for new projects

About Me

Senior Full Stack Engineer with 6+ years of experience, including enterprise telecom work on Deutsche Telekom's Magenta platform and railway ticketing systems. Sole developer on five web platforms: two travel-booking systems, an e-commerce store, an appointment-booking SaaS and a tournament platform. EU-based independent consultancy, available for B2B contracts.

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Tech Stack

Java
Spring Boot
C# / .NET
Vue.js
Vue.js
TypeScript
PostgreSQL
MySQL
Docker
Jenkins
Jenkins
AWS
GCP
Git

Let's Work Together

Have a project idea or need help with your software? Let's build something great together.

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Zagreb, Croatia · Remote
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Booking & Ticketing Systems

End-to-end booking platforms with conflict prevention, multi-tenant architecture and real-time scheduling across locations.

Process Automation & Integrations

Automate workflows and integrate third-party APIs — from payment gateways to international railway ticketing protocols.

SaaS & Web Applications

Scalable, secure multi-tenant SaaS platforms built with modern technologies and deployed on cloud infrastructure.

Maintenance & Support

Ongoing support, performance optimisation and feature development to keep your software running smoothly.

Featured Projects

Recent Work

E-Commerce Platform

E-Commerce Platform

Web Application

Full e-commerce platform with Stripe payments, catalog, cart, checkout and fulfilment. Sole developer, on a 7-service AWS stack (later migrated to GCP).

Spring Boot Vue.js AWS Stripe
Appointment Booking SaaS: the store owner calendar with a week of appointments on a laptop

Appointment Booking SaaS

Web Application

Multi-tenant booking platform with admin, store and customer roles, multiple store locations, double-booking prevention and a full booking lifecycle on GCP. Sole developer.

Spring Boot Vue.js GCP Docker
Tournament Registration Platform: tournament cards with prize, mode, length and entry fee on a laptop

Tournament Registration Platform

Web Application

Call of Duty: Warzone tournament platform built for a client: free, paid and token entry, API-driven scoring and a real-time scoreboard. Sole developer; Azure, later GCP.

Spring Boot Java MySQL GCP
Career Path

Experience

Founder & Full Stack Engineer

Mar 2026 – Present

NextLine · Zagreb, Croatia

  • Founded NextLine, an EU-registered software consultancy handling client acquisition, architecture, development and delivery for international clients.
  • Trilingual client delivery (German, English, Croatian) with straightforward B2B invoicing as an EU-based sole trader with a registered EU VAT ID — no visa or work-permit friction for clients.

Full Stack Engineer

Apr 2024 – Feb 2026

Freelance · Zagreb, Croatia

  • Built an appointment-booking platform for a client as the sole developer, engineering double-booking prevention, email notifications and live-updating schedules.
  • Delivered a business dashboard (staff, services, live appointment schedule) and an admin dashboard with analytics and a control panel for all users, stores, services and categories.
  • Designed, built and deployed an e-commerce store with inventory management, Stripe payments and order fulfilment — on AWS first, later migrated to GCP.
JavaSpring BootVue.jsAWSGCP

Full Stack Engineer

Apr 2023 – Mar 2024

SUPRA Informatika · Zagreb, Croatia

  • Sole developer on two production travel-booking platforms (C#/.NET, MSSQL, Vue) for bus, train and flight search and booking, with secure auth and full API documentation.
  • Joined the team on the company's in-house railway ticketing application with SEPA integration: train creation and scheduling, compartments and seat selection, terminals, tariffs and discounts.
  • Worked with Slovenian, Montenegrin and Deutsche Bahn railway integrations on a platform with 800M-person European market reach.
C#/.NETMSSQLVue.jsREST APIs

Full Stack Engineer

Jan 2022 – Mar 2023

Freelance · Zagreb, Croatia

  • Designed, built and launched an online Call of Duty: Warzone tournament platform for a client as the sole developer: free, paid and token-based entry, solo and team (1–4 players) registration, a virtual token economy and prize pools for the top three places.
  • Integrated the publisher's third-party API to pull player stats (kills, placement) for automatic scoring and a real-time scoreboard.
  • Built with Java/Spring Boot, Thymeleaf and MySQL; deployed on push through an Azure DevOps CI/CD pipeline, later migrated to GCP.
JavaSpring BootMySQLAzure

Full Stack Engineer

Nov 2019 – Dec 2021

Compax · Vienna, Austria

  • Deutsche Telekom Magenta — one of Europe's largest BSS/OSS platforms, serving millions of subscribers: built microservices and workflow-engine components automating contract creation, SIM registration, number provisioning and email notifications.
  • Smart Buy (phone purchases on 6–24-month instalment plans): tracked down and fixed open-connection leaks that were throttling the servers, resulting in fewer timeouts and faster responses.
  • Congstar (DT subsidiary): built new workflow items and composed new workflows from existing ones to fit business cases.
Spring BootJavaOracle SQLJenkinsMongoDB
Contact

Let's Build Something
Great Together

Whether you need a booking system, a SaaS platform, or process automation — I'm here to help. Available for B2B contracts.

Email

Phone

Click to reveal

Location

Zagreb, Croatia · EU-Based · Remote

Languages

German · English · Croatian