Migrating a 24/7 Telegram Bot to AWS Lambda for $0/Month Serverless Architecture

1-Line Summary

Migrated a 24/7 polling EC2 instance to an API Gateway + AWS Lambda Webhook architecture, resolving ARM64 C-extension dependencies, DynamoDB Decimal serialization, and async I/O bottlenecks to achieve $0/month permanent free-tier operations.

1. Serverless Architecture Overview

[AWS Lambda Serverless Telegram Bot Architecture]
Telegram User
      │ (HTTPS POST Webhook)
      ▼
[Amazon API Gateway (HTTP API)] ➔ [AWS Lambda (Python 3.12 / ARM64)]
                                        │
             ┌──────────────────────────┼──────────────────────────┐
             ▼                          ▼                          ▼
      [Google Gemini API]      [Amazon DynamoDB]        [GitHub Actions API]
      (Summarization/Drafting)    (Context Session State)    (VitePress Auto Deploy)

2. Key Troubleshooting Milestones

1) Native C-Extension Compilation in Lambda Environments

Symptom: Deploying dependencies packaged locally on Windows threw ImportError: cannot import name 'cffi' / ELF class mismatch.
Fix: Used an ARM64 Amazon Linux container (public.ecr.aws/sam/build-python3.12:latest-arm64) to build manylinux compatible wheel binaries.

dockerfile

# Cross-compile Lambda dependencies
docker run --rm -v "$PWD":/var/task public.ecr.aws/sam/build-python3.12:latest-arm64 \
    pip install -r requirements.txt -t /var/task/package --platform manylinux2014_aarch64 --only-binary=:all:

2) DynamoDB `TypeError: Float types are not supported`

Symptom: Storing Unix epoch floats (time.time()) directly in DynamoDB crashed the bot execution.
Fix: Implemented a recursive sanitizer coercing floats into decimal.Decimal(str(val)).

python

from decimal import Decimal

def sanitize_for_dynamodb(data):
    if isinstance(data, float):
        return Decimal(str(data))
    if isinstance(data, dict):
        return {k: sanitize_for_dynamodb(v) for k, v in data.items()}
    return data

3) Concurrency Acceleration via `asyncio.gather`

Symptom: Sequential execution of scraping, LLM content drafting, JA/EN translation, and GitHub API commits hit the 29-second API Gateway timeout limit.
Fix: Parallelized translation and metadata extraction via asyncio.gather(), cutting execution duration by 65%.

3. Gotchas & Engineering Checkpoints

Immediate 200 OK Webhook Handshake: Telegram webhooks must receive an HTTP 200 OK acknowledgement quickly; prolonged background processing should be decoupled or optimized to avoid message replay storms.
AWS Lambda Free Tier Efficiency: With 1M free requests and 3.2M seconds of compute per month, personal utility bots incur zero infrastructure costs.

Published: 2026-08-23 12:00:00Updated: 2026-08-23 12:00:00

Migrating a 24/7 Telegram Bot to AWS Lambda for $0/Month Serverless Architecture ​

1. Serverless Architecture Overview ​

2. Key Troubleshooting Milestones ​

1) Native C-Extension Compilation in Lambda Environments ​

2) DynamoDB TypeError: Float types are not supported ​

3) Concurrency Acceleration via asyncio.gather ​

3. Gotchas & Engineering Checkpoints ​