Tomislav Ćalušić

Lead developer on front-office modernization at HPB — Croatian Postal Bank.

Architected and shipped a new Angular SPA replacing a JSF legacy used daily by bank personnel. Designed the secure Spring Boot REST APIs and a custom gateway/routing layer connecting the front-end to core financial back-ends.

Built the real-time integration with HROK (Croatian Credit Information Registry) for mandatory credit-availability checks, plus dynamic in-code PDF generation for regulated documents — credit agreements, compliance reports, account statements — all branded and legally compliant. Owned the Oracle PL/SQL layer, OpenLiberty config, and Jenkins CI/CD pipelines.

Angular · Spring Boot · Java · Oracle PL/SQL · OpenLiberty · Jenkins

Salesforce engagements for three telcos — A1, Telefónica, Liquid Telecom.

Shipped A1 Telecom's eCommerce on Salesforce in agile cycles, built with Apex and Lightning Web Components. Drove a new solution-management process for Telefónica engagements and ran offline client comms. Handled BAU bug-fix and feature work for Liquid Telecom (the largest African telecommunications provider) and contributed to Salesforce admin. Code-driven PDF generation via PDF Butler.

Salesforce · Apex · Lightning Web Components · PDF Butler

Two automotive cloud platforms — Stellantis and Daimler / Mercedes Intelligent Cloud.

Stellantis — Internet of Vehicles. Device-management portal in React + TypeScript with Relay/GraphQL, a Java/Spring Boot application gateway behind it, Next.js + Tailwind on the front-end, and Elasticsearch for querying. Jest for front-end tests.

Daimler / Mercedes Intelligent Cloud. Vue.js + TypeScript front-end and Java/Spring Boot back-end with file converters, end-to-end tests in Cypress and JUnit. Multinational corporate environment with a globally distributed team.

React · TypeScript · Vue.js · Java 11 · Spring Boot · GraphQL/Relay · Next.js · Elasticsearch

Government enterprise platform for tobacco-product traceability.

Helped countries detect illegal smoking products by tracking them from creation to delivery. Three React front-ends — for end users and for the administration team — and Java/Spring Boot REST APIs underneath. PostgreSQL data layer with optimised SQL queries; unit and integration tests in JUnit; Docker on CentOS 7, Maven, Jenkins.

Java · Spring Boot · React · PostgreSQL · JUnit · Docker · Jenkins

Built the back-end for ZgPark — Zagreb's pay-parking-by-phone service.

Designed and developed back-end APIs used by thousands of drivers to buy parking tickets over the phone, plus the admin interface (front + back) used by parking-system operators. MS SQL Server, Tomcat.

Java · XML · MS SQL Server · Tomcat

Two years on the 4G/5G code that carries ~1B mobile subscribers.

Improved and tested cellular network code in an agile team. Optimised legacy C and Java for performance and reduced complexity. Wrote functional and component tests in Erlang and Java (JUnit). Built a shell-pipeline runner using M4 macros and Bash so test suites ran consistently both locally and on Jenkins.

C · Java · Erlang · Bash · M4 · JUnit · Jenkins

Multi-tenant SaaS where each photographer manages a full website by chatting with a Telegram bot.

Bot AS the CMS (not on top of one): every CMS operation is a tool the model can call — uploads, captions, layout, theme, DNS binding. Claude Haiku driving an agentic tool-use loop. FastAPI back-end with raw psycopg3 (no ORM — tenant filtering visible in every query). Caddy with on-demand TLS gated by a /photographers/exists endpoint, so each photographer can point any domain at the same IP and get a cert seconds later. Full case study → (live demo by invitation)

Claude Haiku · FastAPI · psycopg3 · Postgres 16 · Next.js 14 · Cloudflare R2 · Caddy · Docker

Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture.