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Tuhin Poddar
Tuhin Poddar

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Unlocking Backend Simplicity: Building Scalable Apps with Convex

Building scalable, efficient applications can be challenging right ? Specially you have less time or in a hackathon. What if I told you there’s a backend solution that can simplify this process?

Recently I was working on a project where I used the Convex backend for the first time and guess what, it feels simply awesome.

Convex is more than just a database; it’s a comprehensive backend solution tailored for modern developers. It offers everything from cloud functions in TypeScript to real-time data synchronization, enabling you to focus entirely on your front-end code. This has contributed to its growing popularity.

What Sets It Apart 🤔🤔

  • Real-Time Data Sync: The most amazing feature I love most about it is, the real time data synchronization means there is hustle to set up the socket io then send it from backend to frontend. instead here Data is synchronized in real-time between client applications and the database, making it ideal for collaborative or live applications.
  • Serverless Functions: Convex provides serverless functions, called "Convex Functions," which allow you to run backend logic without managing servers. These functions are written in JavaScript or TypeScript.
  • Built-in Authentication: Although there are services like clerk, next auth which works super fine with Next.js + typescript, Convex also supports user authentication, including third-party providers, so you can easily add user login to applications without setting up a custom authentication system.
  • Scalable Database: Convex’s database is automatically scalable and designed to support high concurrency, so it can handle large datasets and traffic spikes.
  • Schema-less Data Model: Convex uses a schema-less data model, allowing you to store flexible data structures, which is beneficial for rapidly evolving projects.

These are the features I personally used and there are many more features like ACID Transactions, TypeScript Support, Security and Access Control, Automatic Caching and Optimization, you can definitely try out.

Now Let’s see how is the approach in normal backend and in a convex backend by a simple getGroupMembers function.

Let’s build a backend function using MongoDB and Node.js

  • First we start by verifying the user’s identity by a typical JWT and for error lets just return 401 Unauthorized response.
  const identity = await verifyToken(req.headers.authorization);
  if (!identity) {
    res.status(401).send("Unauthorized");
    return;
  }

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  • Once the user is authenticated, we retrieve the conversation details. This step involves querying the conversations collection in MongoDB by the provided conversation ID.
  const conversation = await db.collection("conversations").findOne({ _id: conversationId });
  if (!conversation) {
    res.status(404).send("Conversation not found");
    return;
  }

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  • Next, we retrieve all users from the users collection and filter for those whose IDs match the participants in the conversation.
  const users = await db.collection("users").find().toArray();
  const groupMembers = users.filter(user => conversation.participants.includes(user._id));

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  • Finally, we return the list of groupMembers to the client. This data includes only the users who are participants in the specified conversation.
  res.status(200).send(groupMembers);

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Here is the representable diagram of the above code snippet

Normal backend fuction

Let’s build a backend function using Convex

  • Convex provides built-in user authentication with ctx.auth.getUserIdentity(), making it easy to check if a user is logged in. If the user is not authenticated, we throw a ConvexError, which automatically returns an “Unauthorized” response to the client.
  const identity = await ctx.auth.getUserIdentity();
  if (!identity) {
    throw new ConvexError("Unauthorized");
  }

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  • With Convex, database queries are simplified. Using ctx.db.query, we retrieve the conversation by filtering for a match with the provided conversation ID.
  const conversation = await ctx.db.query("conversations")
    .filter((q) => q.eq(q.field("_id"), args.conversationId))
    .first();
  if (!conversation) {
    throw new ConvexError("Conversation not found");
  }

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  • Convex allows us to query all users with ctx.db.query("users").collect(). We then use filter to select only users who are participants in the conversation. Convex’s built-in data retrieval methods make it easier to manage collections without dealing with manual database connection handling.
  const users = await ctx.db.query("users").collect();
  const groupMembers = users.filter((user) => conversation.participants.includes(user._id));

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  • That’s all. Since Convex handles response management, simply returning groupMembers from the function sends the data to the client.
  return groupMembers;

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And here is the overall simplified explanation diagram how convex process the backend -

overall simplified convex architecture

How have I used Convex in my projects

I just recreated freeCodeCamp MERN stack Book Store Project using Next.js, TypeScript, and most importantly, the Convex backend.

So, if you want a good idea of how to use Convex backend then you can follow my github projects where I have shifted my tech stack from MERN stack to NEXT.js + TS + Convex.

  • 𝐁𝐨𝐨𝐤-𝐒𝐭𝐨𝐫𝐞 (𝐌𝐄𝐑𝐍 𝐒𝐭𝐚𝐜𝐤) - Check it out here

  • 𝐁𝐨𝐨𝐤-𝐒𝐭𝐨𝐫𝐞_𝐂𝐨𝐧𝐯𝐞𝐱 (𝐍𝐞𝐱𝐭.𝐣𝐬 + 𝐓𝐒 + 𝐂𝐨𝐧𝐯𝐞𝐱) - Check it out here

if you want you can also visit my LinkedIn post regarding this 🙂🙂.

Conclusion

In short in a traditional backend setup, you manually handle authentication, database connections, queries, and errors, leading to more complex and verbose code. In Convex, these tasks are abstracted, simplifying authentication, database querying, and error management with minimal code, allowing for faster development and cleaner code.

Happy Learning ☺☺!!

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Top comments (2)

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ddebajyati profile image
Debajyati Dey

Great article!
Keep it up!

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tuhin114 profile image
Tuhin Poddar

Thank u 🙂

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