Have you ever ever heard of CNCF’s DevStats? It’s a software that tracks and quantifies all contribution actions inside CNCF initiatives by pulling information from GitHub. Utilizing this information, we will analyze ongoing improvement in CNCF initiatives from a number of views.
One of many key metrics is “Contribution,” which measures actions corresponding to critiques, feedback, commits, points, and pull requests. This enables us to acquire a quantitative measure of the quantity of labor being carried out on a mission. We are able to additionally break down these contributions by nation or by particular person.
On this put up, we study the 2025 DevStats information for Japan, focusing significantly on particular person achievements. Let’s have a look again on the affect Japanese engineers revamped the previous 12 months.
Evaluating with 2024
We ran the same report final 12 months and shared it on our weblog. Since that is our second 12 months doing this, let’s begin with a fast overview of how issues have modified.
Be aware
- DevStats is regularly refining its strategies as information develop, so please remember that there could also be slight discrepancies when evaluating year-over-year.
The initiatives receiving essentially the most Japanese contributions haven’t modified a lot, which exhibits that our group’s areas of curiosity stay constant. Throughout all CNCF initiatives, the whole variety of Japanese contributors was 40. Final 12 months we had over 50, so sadly, the variety of contributors from Japan is on a slight downward development.
Additionally, wanting on the general High 20, the scores aren’t as excessive as they had been final 12 months. For instance, whereas the highest two contributors final 12 months had scores of 8,798 and seven,831, this 12 months’s leaders have scores of 6,463 and 6,176. Whereas absolutely the numbers on the very prime have cooled off, we see a a lot bigger group of individuals within the 500 to 1,000 vary. This implies a shift towards a extra sustainable construction wherein initiatives are supported by a broader staff of constant contributors moderately than by just a few standout people.
High 10 contributors in CNCF initiatives
Listed below are the highest contributors for the 5 CNCF Graduated initiatives which have essentially the most Japanese members. We now have highlighted as much as 10 folks per mission based mostly on their contribution scores.
Be aware
- Aside from Kubernetes, these scores cowl the mission’s complete GitHub group.
- Firm names are based mostly on cncf/gitdm and will not at all times replicate present roles.
Kubernetes
Kubernetes includes many actions that aren’t strictly code, corresponding to translations. Due to this, we’ve separated the info into two classes: the primary kubernetes/kubernetes repository and your entire group.
The kubernetes/kubernetes repository stays the preferred amongst Japanese contributors, with 36 contributors. sanposhiho has proven unimaginable affect right here, reaching a mixed rating of over 1,000 throughout their entries*1.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | sanposhiho | Tetrate.io | 590 |
| 2 | sanposhiho | Unbiased | 466 |
| 3 | toVersus | 3-shake | 223 |
| 4 | utam0k | Most popular Networks Inc. | 201 |
| 5 | sunya-ch | Worldwide Enterprise Machines Company | 143 |
| 6 | everpeace | LY Company | 127 |
| 7 | AkihiroSuda | NTT Company | 114 |
| 8 | mochizuki875 | NTT DATA | 109 |
| 9 | tenzen-y | Unbiased | 105 |
*1: These are seemingly listed individually due to a change in firm affiliation throughout the 12 months.
Kubernetes group (general)
Trying on the group as a complete, tenzen-y took the highest spot with a exceptional rating, simply as they did final 12 months. Whereas the scores on the very prime have leveled off in 2025, the “middle class” of contributors is turning into extra outstanding. This transfer towards a broader base of help is likely one of the most attention-grabbing developments of the 12 months.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | tenzen-y | Unbiased | 4939 |
| 2 | sanposhiho | Tetrate.io | 1122 |
| 3 | sivchari | Unbiased | 789 |
| 4 | sanposhiho | Unbiased | 748 |
| 5 | Okabe-Junya | College of Tsukuba | 716 |
| 6 | shu-mutou | NEC Company | 642 |
| 7 | t-inu | Unbiased | 537 |
| 8 | sunya-ch | Worldwide Enterprise Machines Company | 346 |
| 9 | everpeace | LY Company | 335 |
| 10 | AkihiroSuda | NTT Company | 287 |
fluentd
Fluentd continues to be a mission the place Japanese presence is felt most strongly. Final 12 months, we noticed a number of folks break the 1,000-point mark, and that momentum continued into 2025. daipom, kenhys, and cosmo0920 all maintained excessive scores between 1,000 and 1,500. This can be a subject the place Japan’s long-term dedication could be very steady.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | daipom | Unbiased | 1653 |
| 2 | kenhys | Unbiased | 1392 |
| 3 | cosmo0920 | ClearCode | 1079 |
| 4 | sue445 | Pixiv | 18 |
| 5 | simukappu | Amazon | 13 |
Containerd
In 2024, akihirosuda set a world-class document with a rating of 4,392. Whereas that quantity settled to 2,991 in 2025, he stays the undisputed chief on this house. Japan’s affect on containerd stays huge.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | akihirosuda | NTT Company | 2991 |
| 2 | haytok | Amazon | 121 |
| 3 | yylt | 114 | |
| 4 | utam0k | Most popular Networks Inc. | 13 |
Cilium
Cilium noticed a variety of pleasure in 2024 proper after its commencement, and we noticed a number of Japanese names within the rankings. In 2025, that work has continued steadily, led by yutarohayakawa and ysksuzuki. Whereas the explosive progress in scores has calmed down, it feels just like the mission has moved right into a extra mature section of deep, specialised involvement.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | yutarohayakawa | Isovalent | 513 |
| 2 | ysksuzuki | Isovalent | 282 |
| 3 | shun159 | Amazon | 59 |
| 4 | kahirokunn | Craftsman Software program Inc. | 13 |
Envoy
Japanese contributions to Envoy elevated considerably in 2025, reaching practically 400 factors and incomes it a spot in our report. We’re seeing extra engineers who work throughout a number of initiatives, corresponding to Kubernetes, Cilium, and Envoy, significantly within the community and runtime layers. This versatility is turning into an indicator of Japanese contributors.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | kkk777-7 | CyberAgent Inc. | 264 |
| 2 | anuraaga | Unbiased | 44 |
| 3 | sanposhiho | Tetrate.io | 31 |
| 4 | shikugawa | Tetrate.io | 21 |
Total prime 20 in CNCF
Lastly, listed below are the highest 20 Japanese contributors throughout your entire CNCF ecosystem.
| Rank | GitHub login | Firm | Quantity |
|---|---|---|---|
| 1 | tenzen-y | Unbiased | 6463 |
| 2 | akihirosuda | NTT Company | 6176 |
| 3 | khanhtc1202 | — | 1519 |
| 4 | daipom | Unbiased | 1427 |
| 5 | kenhys | Unbiased | 1248 |
| 6 | sanposhiho | Tetrate.io | 1142 |
| 7 | cosmo0920 | ClearCode | 1025 |
| 8 | sivchari | Unbiased | 1017 |
| 9 | okabe-junya | College of Tsukuba | 944 |
| 10 | utam0k | Most popular Networks Inc. | 911 |
| 11 | ffjlabo | AbemaTV | 887 |
| 12 | sanposhiho | Unbiased | 750 |
| 13 | shu-mutou | NEC Company | 642 |
| 14 | tnorimat | Hitachi Ltd. | 578 |
| 15 | yu-croco | — | 570 |
| 16 | t-inu | Unbiased | 540 |
| 17 | kahirokunn | Craftsman Software program Inc. | 538 |
| 18 | yutarohayakawa | Isovalent | 513 |
| 19 | anuraaga | Unbiased | 463 |
| 20 | sunya-ch | Worldwide Enterprise Machines Company | 433 |
Wrapping up
Constructing on the primary set of knowledge from 2024, this second 12 months of reporting has allowed us to see how the panorama is shifting. Whereas the variety of contributors has declined barely, the core group is turning into stronger and extra various.
The upcoming KubeCon + CloudNativeCon Japan will likely be an enormous enhance for everybody. Internet hosting this occasion domestically will help our present contributors and supply a possibility for newcomers to get entangled.
Each small act, whether or not it’s a code assessment, fixing a typo in documentation, or commenting on a problem, is an actual contribution. We sit up for seeing much more names on this record subsequent 12 months as Japan’s presence within the cloud-native ecosystem continues to develop.
