PeaDB: Redis-Compatible Database Coded with AI Assistants in C++20

Project Overview

PeaDB is a Redis 7.2.5 drop-in replacement written in modern C++20. The developer "vibe-coded" it during Tết (Lunar New Year) with about one week of part-time work while balancing family commitments.

Key Features

• Speaks RESP2/3 protocol
• Implements approximately 147 Redis commands
• Includes persistence, replication, and cluster functionality
• Goal: behave indistinguishably from Redis while optimizing for multi-core CPUs

Development Tools and Cost

The project used a combination of AI coding assistants:

• Codex (ChatGPT Go plan) - $8/month (free via Vietnam promo)
• GitHub Copilot Pro - $10/month
• Total cost: ~1 month of Codex budget + ½ month of Copilot budget

Models used: Claude Opus 4.6, GPT-5.2, and GPT-codex-5.3. The developer noted that Codex 5.3 feels cheaper and sometimes solves problems Opus doesn't, but using all three models together works best.

Three-Model Workflow

For hard problems, the developer used this approach:

1. Ask each model to write opinions/solutions into three separate markdown files
2. Ask Claude to verify, merge, point out mistakes, and learn from the other two models
3. Implement, test, and iterate

Benchmarks and Performance

Benchmark results show PeaDB performance is "quite close to Redis" according to the developer's comparison report. The developer specifically requests critique of their benchmark methodology, asking for feedback on workload mix, client settings, pipelining, CPU pinning, warmup, latency percentiles, and other factors to ensure honest comparisons.

Repository and Resources

The project is available on GitHub, and the developer has provided a detailed comparison report showing benchmark results against Redis.