WCL Examination Platform

Everything that powers the WCL examination at Ramdeobaba University: a sealed desktop client candidates take the exam in, a live control room for administrators, public portals for hall tickets and results, and one API behind them all.

rbuexam.in  |  result.rbuexam.in  |  admin.rbuexam.in  |  api.rbuexam.in

_{The deployment that served these hostnames has been decommissioned.}

Contents

• What this is
• In production
• The five applications
• How exam day works
• Architecture
• Tech stack
• Running it locally
• Production
• Documentation
• Team
• License

What this is

This repository is the complete software stack used to conduct the Western Coalfields Limited (WCL) examination hosted at Ramdeobaba University (RBU), Nagpur. Hundreds of candidates sit the exam at the same time on lab computers, and the platform covers their entire journey: downloading a hall ticket at home, taking a proctored exam in a locked-down fullscreen application, receiving their score the moment the paper is submitted, and looking the result up again afterwards.

This is not a demonstration. The platform has conducted a live examination for real candidates on this infrastructure.

In production

The WCL examination was conducted on 26 July 2026 on the deployment described below.

Candidates registered	574
Candidates who sat the exam	526
Paper	100 questions, 60 minutes, negative marking of 0.5
Submitted by the candidate	340
Auto-submitted by the server at the deadline	186
Sessions left ungraded or unfinished	0
Feedback responses collected	526

Every candidate who began the exam was graded and every result was written. Results were published to result.rbuexam.in after the paper closed.

The five applications

App	Role
app/client	Electron desktop app the candidates take the exam in. Fullscreen kiosk with no title bar and no way out, question images with zoom, offline-tolerant answer saving, and integrity monitoring. Updates itself between releases.
app/admin	Next.js control room: manage questions and their images, import participants, watch live sessions, add time, release device bindings, and export results.
app/hallticket	Next.js public portal where candidates fetch and print their hall ticket PDF before exam day.
app/result	Next.js public portal where candidates look up their score and per-question breakdown once results are published.
app/api	Bun + Express + Drizzle API that owns authentication, exam sessions, answer sync, grading, and feedback. PostgreSQL stores the truth, Redis holds the hot exam state.

How exam day works

1. Before the exam. The candidate opens rbuexam.in, enters their employee id and date of birth, and downloads a hall ticket PDF with their seat allocation.
2. Sitting down. The lab PC launches the exam client straight into fullscreen kiosk mode. The candidate signs in with their assigned credentials and the session binds to that machine, so nobody else can continue it elsewhere.
3. During the exam. The timer runs on the server, so refreshes, crashes, and reboots cannot add time. Every answer is buffered locally and synced continuously, so nothing is lost if a machine dies mid-click. Leaving fullscreen, switching windows, or losing focus is recorded as an integrity event that proctors see live.
4. If a PC fails. A proctor presses Release device in the admin panel, the candidate logs in on any other machine, and every answer, every mark for review, and the running clock resume exactly where they left off.
5. Submitting. Grading happens instantly on the server, with negative marking of 0.5 per wrong answer. The candidate sees their final score, rates the platform and the venue, and the application closes itself, leaving the seat ready for the next candidate.
6. The deadline. Anyone still writing at the deadline is auto-submitted by the server, even if their machine is powered off. On exam day this accounted for 186 of the 526 papers.
7. Afterwards. Once an administrator publishes results, candidates sign in at result.rbuexam.in with the same employee id and date of birth to see their score again, along with every question they were served and the correct answer. Nothing is disclosed before that switch is flipped.

Architecture

flowchart LR
    K["Exam client<br/>Electron kiosk on lab PCs"] -->|HTTPS| LB
    B["Candidate and admin<br/>browsers"] -->|HTTPS| LB

    subgraph AWS["AWS ap-south-1"]
        direction LR
        LB["Application Load Balancer<br/>one TLS certificate,<br/>routing by host name"]

        subgraph FE["Frontend EC2<br/>Docker, watchtower"]
            direction TB
            HT["Hall ticket portal<br/>rbuexam.in"]
            RS["Result portal<br/>result.rbuexam.in"]
            AD["Admin panel<br/>admin.rbuexam.in"]
        end

        subgraph BE["Backend EC2<br/>Docker, watchtower"]
            direction TB
            API["API<br/>api.rbuexam.in"]
            OBS["Observability<br/>Grafana, Prometheus, Loki<br/>grafana.rbuexam.in"]
        end

        subgraph DATA["Managed data"]
            direction TB
            PG[("PostgreSQL<br/>Amazon RDS")]
            RD[("Redis<br/>ElastiCache")]
            S3[("Amazon S3<br/>question images")]
        end

        LB --> HT
        LB --> RS
        LB --> AD
        LB --> API
        LB --> OBS
        API --> PG
        API --> RD
        API --> S3
        HT --> PG
        RS --> PG
    end

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The infrastructure is codified as Terraform in terraform/, and the full network design (VPC, security groups, data flows) is explained in docs/ARCHITECTURE.md.

Server deploys are cut deliberately with ./release.sh <service>, which tags a version; the exam client ships on every push to main:

flowchart LR
    T["release.sh tag"] --> GA["GitHub Actions"]
    P["Push to main"] --> GA
    GA -->|Docker images| DH["Docker Hub"]
    DH -->|pulled by watchtower| SRV["EC2 services"]
    GA -->|Windows installer| GR["GitHub Releases"]
    GR -->|electron-updater| EX["Installed exam clients"]

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Tech stack

Bun, TypeScript, Express, Drizzle ORM, PostgreSQL, Redis, Next.js, React, Tailwind CSS, shadcn/ui, Electron, electron-vite, Docker, GitHub Actions, Terraform, Grafana, Prometheus, Loki, and AWS (EC2, ALB, RDS, ElastiCache, S3, Route 53, ACM).

Running it locally

Prerequisites: Bun plus PostgreSQL and Redis (Docker works well for both).

App	Start	Serves
API	cd app/api && bun install && bun run db:migrate && bun run seed && bun run dev	http://localhost:4000
Admin	cd app/admin && bun install && bun run dev	http://localhost:5000
Hall ticket	cd app/hallticket && bun install && bun run dev	http://localhost:5001
Result	cd app/result && bun install && bun run dev	http://localhost:5002
Client	cd app/client && bun install && bun run dev	desktop window

Each app ships a .env.example describing its configuration and a README with the details. Everything defaults to the local API at port 4000.

Production

The examination is over and the production environment has been decommissioned. The hostnames below served the platform on exam day and are listed as a record of the deployment; none of them resolve to infrastructure we operate any more.

Hostname	Service
rbuexam.in	Hall ticket portal
result.rbuexam.in	Result portal
admin.rbuexam.in	Admin panel
api.rbuexam.in	API
grafana.rbuexam.in	Grafana dashboards

The stack runs locally from this repository exactly as it did in production; see Running it locally.

Documentation

Document	Contents
docs/API.md	Full API reference
docs/RUNBOOK.md	Operations runbook for exam day
docs/NEW_EXAM.md	Setting up a new exam from scratch
docs/FEEDBACK.md	Post-submission candidate feedback
docs/KIOSK_LOCKDOWN.md	How the client lockdown works
docs/ARCHITECTURE.md	Network design, security groups, and data flows
docs/DEPLOY_FRONTEND.md	Frontend infrastructure and deployment
docs/DEPLOY_BACKEND.md	Backend infrastructure and deployment
docs/OBSERVABILITY.md	Logs, metrics, and dashboards
docs/RULES.md	Writing rules for prose in this repository

Team

Built and maintained by Bhuvnesh Verma and Vivian Demello.

Code ownership per path is declared in .github/CODEOWNERS, which GitHub uses to request the right reviewer automatically on every pull request.

License

Copyright (c) 2026 Bhuvnesh Verma and Vivian Demello. All rights reserved.

The source is published so it can be read and studied. It is not open source: using, copying, modifying, or redistributing it requires written permission from both copyright holders. See LICENSE for the full terms.