I believe most of new online casino uses a Java Script due to HTML5 that has a faster internet speed which loads the games pretty fast. Old casino is more likely written in C or C++ with built in flash applications. I wonder why OP asked for this, kinda shady for me given that it does not matter at all unless you are going to break their code? The only thing that I can see why you're asking for this is that some languages aren't built for browsers.
How can anybody break a casino's code by knowing the tech they used? Maybe by knowing a bug about the tech that nobody knows yet? Maybe...
To answer the OP's question:
Front-end is always pure js or a js framework like react, vue etc.
Back-end is either php, node or django/flask, rarely java or something else. Most of the time it's node or php.
Databases can be anything, mysql or mongo...
Anyway this is the topic you are looking for probably, if anybody hasn't linked it yet:
https://bitcointalk.org/index.php?topic=792805.0Busy gambling sites need to provide high security as well as serve high traffic. In which language today's top sites are coded ? Which DB are they using ?
I'm listing a few sites below. Please post if u know about their configuration. If u know about a site which is not in the list, please post that too...
Following table is updated as per latest data found in this thread...
Site | Server | Backend | Socket lib | DB/Storage | Frontend |
Just-Dice.com | | Node.js | socket.io | redis+MySQL | |
PrimeDice.com | Cowboy | Node.js | socket.io | PostgreSQL | EmberJS |
DiceBitco.in | nginx | Node.js+Express | Primus | | AngularJS |
Dicenow.com | nginx | Node.js+Express | socket.io | | AngularJS |
Satoshibet.com | nginx | Node.js | socket.io | mySQL+mongoDB | |
MoneyPot.com | Cowboy | Node.js | socket.io | PostgreSQL | React |
PRCDice.eu | MS-IIS | .NET | SignalR | | |
Win88.me | MS-IIS | .NET | ServiceStack | | AngularJS |
Peerbet.org | MS-IIS | .NET | --- | | |
Dice.ninja | cyclone | Python | sockjs-cyclone | MySQL | |
luckyb.it | | Python+Flask | --- | | |
Rollin.io | Apache | PHP+laravel | socket.io | | |
BitDice.me | nginx | RoR+RabbitMQ | | Redis+MySQL | |
PocketDice.io | nginx | PHP | socket.io | --- | AngularJS |
FastSlots.co | vanilla | node.js | socket.io | mySQL | backbone |
FastDice.com | Apache | PHP | --- | --- | --- |
777Coin.com | --- | PHP | --- | --- | --- |
Bitvest.io | --- | PHP | --- | --- | --- |