TaskFlow

A small task & project management application: a React frontend backed by a Spring Boot REST API and PostgreSQL.

Users own projects, projects contain tasks, tasks are assigned to users and can carry comments. The frontend lets you browse projects and toggle task completion.

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The assessment

This codebase works in places and is broken in others. It was written quickly and never reviewed. Your job is to act as the senior engineer who picks it up.

We would like you to:

1. Get it running locally (instructions below).
2. Find the defects. They span the full stack — React state and effects, the REST API contract, JPA/persistence behaviour, query performance, and security. Some are obvious; several are not.
3. Fix them. Make the changes you would make on a real team, and keep the code idiomatic.
4. Explain your work. For each issue, briefly note in FINDINGS.md (create it): where it was, why it was wrong, the impact, and how you fixed it.

We care more about how you reason than about catching every last item. Prioritise, and call out anything you would do with more time.

There is no fixed bug count given to you on purpose. Treat it like a real codebase.

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Tech stack

Layer	Technology
Frontend	React 18 + Vite
Backend	Spring Boot 3, Spring Data JPA
Database	PostgreSQL 16

Prerequisites

Pick whichever fits what you have installed:

• Run everything in Docker (recommended): just Docker (Docker Desktop or equivalent). Nothing else required.
• Run locally: Java 17+ (JDK), Node 18+ with npm, and PostgreSQL 16 (or use Docker for just the database).

Running it — Option 1: everything in Docker (one command)

docker compose up

This builds and starts all three services together — PostgreSQL, the Spring Boot backend, and the React frontend. The first run downloads dependencies and may take a few minutes; later runs are fast.

Once it's up:

• Frontend: http://localhost:5173
• Backend API: http://localhost:8080
• Database: runs inside the Compose network (not exposed on your host, so it won't clash with any Postgres you already run).

Your source is mounted into the containers, so you can edit and see changes:

• Frontend changes hot-reload automatically (Vite HMR).
• Backend (Java) changes: run docker compose restart backend to pick them up (Spring recompiles on start). Reliable auto-reload for Java across Docker's file sharing is flaky, so a quick restart is the dependable path.

Stop with Ctrl-C, or docker compose down (add -v to also wipe the database).

Running it — Option 2: locally (without Docker for the app)

1. Start PostgreSQL — pick ONE

A. Docker, database only:

docker compose up -d db

Or B. a local PostgreSQL — create the role and database the app expects:

createuser taskflow --pwprompt        # set the password to: taskflow
createdb taskflow --owner taskflow

…or from psql as a superuser:

CREATE USER taskflow WITH PASSWORD 'taskflow';
CREATE DATABASE taskflow OWNER taskflow;

The backend reads its connection from backend/src/main/resources/application.yml (jdbc:postgresql://localhost:5432/taskflow, user/password taskflow/taskflow). To point at a different host/port/credentials without editing that file, set the standard Spring env vars, e.g.:

SPRING_DATASOURCE_URL=jdbc:postgresql://localhost:5433/taskflow ./mvnw spring-boot:run

Note: Option 2's local-DB step expects Postgres on the host's port 5432. The Docker-only-DB variant above (docker compose up -d db) does not publish a host port (the full stack talks to it internally), so if you want to connect a locally-run backend to the Dockerised DB, publish a port for it or use Option 1.

2. Backend

cd backend
./mvnw spring-boot:run        # Windows: mvnw.cmd spring-boot:run   (Maven users: mvn spring-boot:run)

The API comes up on http://localhost:8080. On first start the schema is created and seed data is loaded automatically — no manual migration step.

3. Frontend

cd frontend
npm install
npm run dev

The app is served at http://localhost:5173. It calls the backend at http://localhost:8080 (configured in frontend/src/api/client.js).

Troubleshooting

• Reset the database: docker compose down -v then bring it back up.
• Backend can't connect (local run): make sure PostgreSQL is running and reachable before starting the backend.
• Ports 8080 / 5173 already in use: stop whatever is using them (or a previous run of this app) first.

API overview

Method	Path	Description
GET	/api/projects	List all projects
GET	/api/projects/{id}	Get a single project
POST	/api/projects	Create a project
GET	/api/projects/{id}/tasks	List tasks in a project
GET	/api/projects/{id}/task-summaries	Lightweight task summaries
POST	/api/projects/{id}/tasks	Create a task
PUT	/api/tasks/{id}/status?status=DONE	Update a task's status
GET	/api/tasks/search?q=...	Search tasks by title
POST	/api/auth/register	Register a user
POST	/api/auth/login	Log in

Seeded accounts

Username	Password
alice	password123
bob	hunter2
carol	letmein
dave	qwerty1
erin	sunshine

Deliverable

A branch or archive with your fixes, plus FINDINGS.md. Good luck!