---
title: "Atsumasa Kobayashi (@atsumasa-k)"
description: "Rank #2185 of 2498 on the Paradev leaderboard, tier 1."
canonical: https://paradev.com/atsumasa-k
last-updated: 2026-10-26
---

# Atsumasa Kobayashi (@atsumasa-k)

Rank #2185 of 2498 on the Paradev leaderboard, tier 1.

URL: https://paradev.com/atsumasa-k

## Standing

- Rank: #2185 of 2498
- Tier: Button pusher
- Tokens: 1.26B all time
- Cost: $2147.65 API-equivalent
- Sessions: 1379
- Tracking: 2026-07-29 to 2026-10-25

## How this tier was reached

Tier is a weighted score across the axes measured for you, so a strong axis offsets a weak one. Operator needs a higher combined score, and cost also caps the tier on its own.
Scored on 3 axes, measured over the trailing 30 days.

| Axis | Current | Needed | Met | Measures |
| --- | --- | --- | --- | --- |
| width | 1.0 | 3.1 | no | agents running at once |
| depth | 775.7K | 10.4M | no | tokens per session |
| sustain | 22 | 17 | yes | active days in the last 30 |

## Achievements

- **thirty** (level 1 of 3) at 30, earned 2026-09-07
- **two-hands** (level 1 of 3) at 10, earned 2026-09-07

## Milestones

- sessions: 1.0K
- spend: 1.0K
- tokens: 100.0M

## Contributions

- Active days in the last year: 64
- Busiest day: 2026-08-28 at 145.3M tokens

## Models

| Provider | Model | Tokens | Cost |
| --- | --- | --- | --- |
| claude | claude-fable-5 | 447.4M | $1206.71 |
| claude | claude-sonnet-5 | 423.8M | $436.00 |
| claude | claude-fable-5-1 | 190.1M | $332.32 |
| claude | claude-opus-5 | 68.8M | $77.36 |
| claude | claude-haiku-4-5-20251001 | 61.6M | $25.36 |
| claude | claude-opus-5-5 | 32.7M | $22.50 |
| claude | claude-opus-4-7 | 8.0M | $13.66 |
| codex | gpt-5.6-sol | 7.5M | $14.24 |

## Token breakdown

- Uncached input: 1.9M
- Cached input: 1.14B
- Cache write 5m: 28.4M
- Cache write 1h: 66.8M
- Output: 18.2M
- Reasoning output: 6.3M

Published voluntarily by the account holder. Source: https://paradev.com/atsumasa-k