nexus - ~/projects/nexusClose

Nexus Platform

Bachelor's thesis, successfully defended July 2026 · Ss. Cyril and Methodius University in Skopje, Faculty of Computer Science and Engineering (FINKI)

In short

Nexus Platform is a modular, multi-tenant ERP: a business subscribes and switches on only the modules it needs. It is built from Java 21 microservices. I designed and built it end to end as my Bachelor's thesis. It is my worked example of architecture and infrastructure, and I spent a long time on it.

The problem

Business software has to serve many organisations at once without any of them seeing another's data, and it has to grow by adding new modules without rewriting the core. The thesis asks how to build that: strict data isolation between tenants, services that deploy independently, central sign-in, and new modules that register themselves.

My role

I designed and built the whole system myself, and wrote the thesis.

What I built

  1. The platform core: an API gateway that checks every request's token, service discovery and a central config service.
  2. Sign-in with JWT tokens. The gateway reads the tenant from the token and passes it on, so services never decode tokens themselves.
  3. Tenant, user and role services, and a module registry: a new module announces itself when it starts, and the menu in the interface builds itself from the registry.
  4. An audit service that records platform events, and a notification service.
  5. Four business modules: Organization (departments, positions, employees), Master Data (products, customers, suppliers), Inventory (warehouses, stock levels, receipts, issues) and Finance (chart of accounts, journal entries, ledger).
  6. A React interface for all of it, and monitoring with tracing, metrics, dashboards and central logs.

How it is built

Java 21 with Spring Boot and Spring Cloud (Gateway, Eureka, Config), PostgreSQL, and Apache Kafka for events between services.Observability uses Zipkin, Prometheus, Grafana and Logstash with Elasticsearch.The frontend is React with TypeScript, Vite and Tailwind CSS.The whole stack starts with Docker Compose.

A hard decision, and what I left out

Tenants share the same tables, and every row carries a tenant ID that is applied automatically to every query. It is simpler than a database or schema per tenant, and it needs discipline, so the tenant context is set once at the edge and cleared after each request. Finance refuses an unbalanced journal entry on both the client and the server, and Inventory refuses to issue stock it does not have. I tested the service layer with unit tests rather than container-based integration tests, because the Docker version on my development machine was not compatible with the test containers I needed. Building out the platform beyond four modules was left for later.

Result

Bachelor's thesis, successfully defended on 2 July 2026 at FINKI.

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Slavcho Mickovski. Software engineer.

I build web applications, and I design the architecture and infrastructure behind them. Here is what I have built.

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What I have built

  • Founders & partners

    Shopest

    A multi-tenant e-commerce web application platform: many separate online stores on one system. I built the entire frontend and designed the UI/UX.

    Read the case study
  • Own product

    Vidilaptopi

    A web app that gathers laptop data from different Macedonian online shops, processes it into one catalog, and lets you compare prices and specs. I built the web app, with help from a friend on the design and part of the code.

    Read the case study
  • Bachelor's thesis

    Nexus Platform

    A modular, multi-tenant ERP made of Java 21 microservices: my worked example of architecture and infrastructure, and a project I spent a long time on. I designed and built it end to end.

    Read the case study
  • Personal tool

    Eniac

    A finished tool I built where AI agents plan and write code and I approve every step.

    Read the case study

languages

  • Java 21
  • TypeScript
  • PHP 8.4
  • Python

frontend

  • React 19, Vite
  • Angular
  • Material UI, Tailwind CSS
  • UI/UX design

backend

  • Spring Boot, Spring Cloud
  • Laravel 12, FastAPI
  • Apache Kafka
  • JWT and token authentication
  • microservices, API gateway

data

  • PostgreSQL, SQLite
  • multi-tenant data isolation

infrastructure and ops

  • Docker, Docker Compose
  • GitLab CI
  • Zipkin, Prometheus, Grafana
  • Logstash, Elasticsearch
  • Cloudflare Turnstile

About me

I'm Slavcho Mickovski, a software engineer based in North Macedonia. I have a Bachelor in Computer Science and Engineering, majoring in Software Engineering and Information Systems, from the Faculty of Computer Science and Engineering (FINKI) at Ss. Cyril and Methodius University in Skopje.

I build web applications, and I design the architecture and infrastructure behind them. On this site you can see four of my projects: an e-commerce platform, a laptop price comparison, an ERP built from Java 21 microservices, and a tool for working with AI agents.

I build the work myself and I answer my email myself.

Get in touch

Email is the best way to reach me.

mickovski.studio@gmail.com

Email me