Insider One Champions League

A football league simulator built for the Insider technical case. It generates a fixture for four teams, simulates matches based on team strength, tracks the league table with Premier League rules and predicts championship odds using a Monte Carlo simulation.

Live Demo

• Frontend: https://insider-league.vercel.app/
• API: https://insider-league-production.up.railway.app/api/standings

Tech Stack

• Backend: Laravel (PHP 8.4), PostgreSQL, PHPUnit
• Frontend: Vue 3, TypeScript, Pinia, Vite, Vitest
• Infrastructure: Docker, docker-compose

Features

• Round-robin fixture generation (home & away, six weeks)
• Match simulation weighted by team strength where weaker teams still have a chance to win
• League standings with points, goal difference and Premier League tie-breakers
• Monte Carlo championship prediction (shown from week 4)
• Play next week, play all weeks and reset
• Unit tests on both backend and frontend

Architecture

The core logic lives in framework-independent service classes which keeps it testable and easy to reason about:

• FixtureGenerator — builds the round-robin schedule
• MatchSimulator — produces a score from two team strengths
• StandingsCalculator — computes and orders the table from played matches
• ChampionshipPredictor — runs Monte Carlo simulations of the remaining matches
• LeagueService — coordinates these services and persists results

The frontend follows a container/presentational pattern. Pinia store holds the shared state and presentational components receive data via props and emit user events upward.

Running with Docker

The whole stack (backend, frontend, database) runs with a single command:

docker-compose up --build

• Frontend: http://localhost:5173
• API: http://localhost:8000/api

Running Manually

Backend

cd backend
composer install
php artisan migrate --seed
php artisan serve

Frontend

cd frontend
npm install
npm run dev

Running Tests

Backend

cd backend
php artisan test

Frontend

cd frontend
npm run test:unit

Notes & Assumptions

• The league has four fixed teams with predefined strengths. The fixture algorithm is written generically so the team count does not break it.
• Championship predictions are calculated at all times but only displayed from week 4 as described in the case.
• The match simulation is intentionally simple but reflects the brief. Stronger teams win more often while weaker teams still have a realistic chance to win.