The architecture of a simple Telegram bot: what to store, what to log

Imagine: you decided to write a Telegram bot. For example, a bot for receiving orders, collecting orders, automating support or notifications.

Everything looks simple at the start. You write a message handler, connect webhook or polling, and the bot already responds to the user.

But after a few days, questions arise:

• where to store users
• do i need to keep messages
• how to understand why the bot fell
• how to track errors
• what events to log

This is where the bot architecture begins.

Even a simple Telegram bot should have a clear structure of data storage and logging. Without this, the project quickly turns into chaos: it is difficult to find errors, it is difficult to analyze user behavior and it is difficult to scale the system.

In this article, we will examine:

• what parts is the architecture of the Telegram-bot
• which data must be stored
• which data is better not to store
• what events should be logged
• how to organize database tables
• how to set up a logging system
• common mistakes in bot development

## Basic architecture of the Telegram bot

In fact, the architecture of a simple bot is quite minimalist. It usually consists of several components.

The simple flow of work looks like this:

1. The user sends a message to the bot.
2. Telegram sends update to your server.
3. Backend handles the update.
4. The bot performs an action (response, record in the database, etc.).
5. The event is logged.

### Example of Telegram update

{
  "update_id": 123456,
  "message": {
    "message_id": 55,
    "from": {
      "id": 123456789,
      "username": "alex"
    },
    "text": "/start"
  }
}

Each update contains information about the user, message and event.

## What data must be stored

Many novice developers try to save everything. But in practice, you only need to store data that is actually used in the logic of the bot.

### The main essence of the Telegram-bot

The minimum set of tables usually looks like this:

### User table

This table stores information about people who interact with the bot.

Example of SQL table:

CREATE TABLE users (
  id SERIAL PRIMARY KEY,
  telegram_id BIGINT UNIQUE,
  username TEXT,
  first_name TEXT,
  created_at TIMESTAMP
);

Why it is important to keep the user:

• activity can be tracked
• you can send notifications
• you can analyze the audience of the bot.

### User status table

If the bot contains scripts (for example, questionnaires, menus, checkout), you need to store the current state of the user**.

Example of conditions:

This allows the bot to understand the context of the dialogue.

### Table of user actions

Sometimes it’s helpful to save user actions for analytics.

For example:

Such a table helps to analyze the behavior of users.

## What data should not be stored

Beginners often make one mistake: *Save every user message..

It's almost always superfluous.

Telegram already stores the history of messages, and most bots do not need this information.

### When not to save messages

### When messages are useful to store

Storing all messages increases:

• baseload
• processing
• cost of infrastructure.

## What must be logged

Logs are the main diagnostic tool.

Without logs, you can't understand:

• why did the bot stop responding
• why is webhook not working
• where the error occurs.

### Minimum set of logs

### Example of logging update

logger.info("telegram update", {
  update_id: update.update_id,
  user_id: update.message?.from?.id
})

This helps to track the flow of events.

### Logistic of errors

Mistakes are the most important thing to log.

Example:

try {
  await bot.sendMessage(chatId, text)
} catch (error) {
  logger.error("telegram send error", {
    chatId,
    error: error.message
  })
}

Without such logging, debugging becomes almost impossible.

## Good bot logging scheme

Practice shows that three types of logs are enough.

Example of structure:

## Typical bot project architecture

A good design might look like this.

This structure makes the project understandable and supported.

## Typical mistakes in the development of Telegram bots

Novice developers often make the same mistakes.

### Keeping everything together

### Lack of logging

### Lack of user status

## How to apply it through AI

AI assistants can greatly accelerate the development of Telegram bots.

For example, you can ask the model to create an architecture.

Example:

I'm building a Telegram bot.

You need to offer backend architecture.

Conditions:
store users
- keep the state of the script
Log out errors and events
Use PostgreSQL

Show the structure of the tables and an example of logging.

This approach allows you to quickly get the basis of the project.

## Outcome

The architecture of a Telegram bot doesn’t have to be complicated.

But even a simple bot should have a clear structure of data storage and logging.

The minimal architecture looks like this:

If these principles are followed, the bot will:

• ease up
• scale
• it's easier to analyze.