OSS Gravity Map

Do Physical Laws Exist in the Universe of Code?

Cross-analysis of 29 repositories, 55,343 engineers, and 5 language families

29 Repos 55,343 Engineers 5 Categories 4.8x Gravity Gap
Contents
1. What is EIS? 2. Cross-Language Analysis — Physical Laws Are Not Uniform Gravity Concentration Three Structural Authority Modes 3. Rails vs Laravel — Same Category, Opposite Physics 4. esbuild — A Universe of One 5. React — A Decade of Generational Transition 6. Validity of EIS — Does Intuition Match Data? 7. Conclusion

1. What is EIS?

EIS (Engineering Impact Signal) is a CLI tool that quantifies the "structural influence" an engineer has left on a codebase, using only data from git log and git blame.

GRAVITY Structural Influence Signal Indispensability × 0.40 The degree to which no one else has written that code Breadth × 0.30 How broadly an engineer touched across the codebase Design × 0.30 How deeply involved in foundational design files Data source: git log + git blame only

In this analysis, we use Gravity Concentration (what percentage of total Gravity the top 10 engineers hold) as the cross-language comparison metric.

2. Cross-Language Analysis — Physical Laws Are Not Uniform

Different languages produce different "physical laws." Type system expressiveness, framework culture, and architectural concentration.
We classified 29 OSS repositories into 5 categories and compared the distribution of structural authority.

29
Repositories
55,343
Engineers
4.8x
Gravity Gap
5
Categories
CategoryCharacteristicsLanguagesRepos
ExpressiveRich type systems, ADTs, pattern matching, traitsRust, Scala5
Go (Self-structured)Static typing, anti-framework culture, explicit interfacesGo7
Framework-drivenStructure delegated to frameworks, CoCRuby, PHP, Java, Python, TS, Elixir6
Systems (C/C++)Manual memory management, templatesC, C++5
Dynamic / StructuralDynamic typing, self-structuredJavaScript, TypeScript, Python6

Gravity Concentration

What percentage of total Gravity is held by the top 10 engineers. Higher values mean "structure is concentrated in fewer architects."

Go (Self-structured)
16.4%
Dynamic / Structural
10.4%
Expressive
6.7%
Framework-driven
5.1%
Systems (C/C++)
3.4%
Go concentrates gravity; expressive type systems distribute it.
Go's anti-framework culture means someone has to build structure from scratch. And that structural authority concentrates in a few architects.
In contrast, Rust and Scala's type systems can encode design decisions themselves, distributing structural authority more broadly. The type system acts as a distributed architect.

Three Structural Authority Modes

Architect-centric (Go)

Structure is built by "people." A few architects hold overwhelming design authority. Concentration: High.

Type-distributed (Rust/Scala)

Structure is embedded in "types." Design authority is distributed across everyone who writes type signatures. Concentration: Low.

Framework-absorbed (Rails/Laravel)

Structure is absorbed by the framework. However, internal governance spans a spectrum from distributed to concentrated.

Framework

3. Rails vs Laravel — Same Category, Opposite Physics

Both belong to the "Framework-driven" category. Both are popular frameworks with legendary creators.
Yet their Gravity physics are completely opposite.

Rails
Multi-Architect Civilization
Engineers6,512
Top10 Design51.2
Top10 Survival7.3
Gravity Conc.0.9%
Design > 356 people
Laravel
Kingdom of the Creator
Engineers4,449
Top10 Design17.2
Top10 Survival15.3
Gravity Conc.1.5%
Design > 351 person

Design Authority Distribution

Rails — 6 Architects
DHH
100.0
Jeremy Kemper
89.0
Rafael Franca
68.4
Aaron Patterson
54.0
Xavier Noria
45.8
Jose Valim
39.4
── Design 35 Threshold ──
Laravel — Taylor Otwell's Monopoly
Taylor Otwell
100.0
Graham Campbell
63.1
── All other Top10 contributors: Design < 4 ──
Lucas Michot
3.5
Tim MacDonald
2.6
Same Framework-driven category. Completely opposite governance physics.

Rails achieved architect succession over 20+ years. The structure DHH created is now distributed across 6 architects. Top10 Design of 51.2 is higher than most Go projects.

Laravel is a creator-centric kingdom. Taylor Otwell's consistent vision minimizes churn (Survival 15.3 > Rails 7.3). Efficient, but the bus factor for structural authority is 1.

The question isn't which is better, but why the same pattern produces opposite physics.

4. esbuild — A Universe of One (Gravitational Singularity)

125 contributors exist, but one person holds 92.5% of all structural gravity.

92.5%
Gravity Concentration
100
All-axis Impact
4,208
Evan Wallace commits
0
#2's Design
Evan Wallace Gravity 100 | Design 100 | Indisp 100 | Survival 100 124 other contributors All Design: 0, Indisp: 0 Gold area = 92.5% of total project gravity

How Extreme 92.5% Really Is

esbuild
92.5%
express
23.9%
swc
15.7%
vite
9.3%
react
3.4%
rails
0.9%
kubernetes
0.8%
rust
0.6%
A singularity is powerful, but succession planning is impossible.
esbuild proves that a single genius architect can build an entire universe. A demonstration that JS bundling can be 10-100x faster.
115x more concentrated than Kubernetes, 103x more than Rails. This isn't a matter of scale — the very nature of the project is fundamentally different.

5. React — A Decade of Generational Transition

React, with 2,010 engineers involved, has undergone 5 generations of architect transitions over 10 years.
Using EIS's timeline feature to track Gravity in 3-month spans, the moments of generational transition become visible.

2,010
Engineers
3.4%
Gravity Concentration
5
Generational Shifts
10 yrs
Tracking Period

Generational Timeline of Anchors (Structural Pillars)

2013-2015 — Genesis
Paul O'Shannessy led the initial virtual DOM implementation. Activity largely ceased afterward.
The person who gave shape to the virtual DOM idea departed as the project grew.
2016-2017 — First Generational Shift
Dan Abramov (Redux creator) and Andrew Clark rose to prominence.
Dan: Gravity 64.0, Design 54.0 — Led the renewal of React's philosophy and API.
The transition to Fiber Architecture. External contributors transforming the internal architecture.
2018-2020 — Stabilization
Brian Vaughn built the DevTools and profiling infrastructure. Design 36.6.
The person who built the foundation of developer experience. Supporting the infrastructure during the Hooks era.
2021-2023 — Second Generational Shift
Sebastian Markbåge and lauren took center stage.
Server Components, Suspense, new rendering pipeline.
Dan Abramov departed (2024). React's design authority quietly transitioned to the next generation.
2025 — Latest Generation
Jorge Cabiedes — Design 100, with just 82 commits.
It's not how many commits you make, but "where" you write code that determines structural influence.
Evidence that EIS correctly captures quality (structural impact) over quantity.
React's generational transition is a model case of a healthy OSS project.

Initial virtual DOM implementer → Hooks/Fiber leaders → DevTools builder → Server Components architects → current structural designers.
When one person leaves, the next generation seamlessly inherits structural authority. Gravity Concentration of 3.4% is the result of this distributed governance.

And Jorge Cabiedes: Design 100 with 82 commits. Even with few commits, if you write code that touches the core of the design, EIS measures it precisely.

6. Validity of EIS — Does Intuition Match Data?

EIS is computed solely from git log and git blame. It cannot see RFCs or design documents.
Yet the results are surprisingly consistent with community intuition.

Validation ItemEIS ResultCommunity IntuitionMatch
Rails design distributionTop10 Design 51.2, 6 architects"Rails has a deep core team"Match
Laravel design concentrationTaylor Otwell = Design 100, all others < 4"Laravel is Taylor's creation"Match
esbuild's solo nature92.5% concentration, Evan Wallace all-axis 100"esbuild was built by Evan alone"Match
Kubernetes distributionGravity Conc. 0.8%"K8s has a massive community"Match
React's generational shifts5 Anchor transitions over 10 years"React is constantly evolving"Match
Jorge CabiedesDesign 100 with 82 commitsEmbodiment of "quality over quantity"Match
Go vs Rust concentrationGo 16.4% vs Rust/Scala 6.7%"Go relies on few architects for design"Match
Beyond "it feels about right."

EIS is not perfect. RFC discussions, design conversations on Slack, mentoring through code reviews — this "dark matter" is unobservable.
Yet even through the limited lens of git blame, it reflects the structural truth of a project with surprising accuracy.

Results across 29 repositories and 55,343 engineers show that the physical laws of structural authority differ systematically across language families. This is an insight that could not be quantified through experience and intuition alone.

7. Conclusion

Physical Laws Exist in the Universe of Code

Gravity concentration varies by 4.8x across language families — from Go (16.4%) to Systems C/C++ (3.4%).

Three structural authority modes — Architect-centric (Go), Type-distributed (Rust/Scala), Framework-absorbed (Rails/Laravel) — show that even when code looks similar, the physics of structural authority are fundamentally different.

Even within the same Framework-driven category, Rails and Laravel exhibit opposite governance physics. esbuild is a singularity where physical laws break down. React achieved healthy generational transition over 10 years.

Knowing which physical laws govern your universe is the first step toward better structural decisions.

All 29 Repositories

RepositoryCategoryLanguageEngineersTop10 DesignTop10 SurvivalGrav Conc
esbuildGoGo12510.010.092.5%
expressDynamicJS39113.53.223.9%
swcExpressiveRust35716.414.015.7%
prettierDynamicJS79942.910.013.4%
fastapiFrameworkPython89711.711.29.4%
viteDynamicTS1,24732.616.09.3%
eslintDynamicJS1,18018.612.88.1%
lokiGoGo1,31934.019.37.8%
spring-bootFrameworkJava1,50430.234.17.3%
polarsExpressiveRust69417.429.87.0%
nestFrameworkTS68413.310.27.0%
scalaExpressiveScala79432.35.96.8%
prometheusGoGo1,28144.511.95.4%
supersetDynamicPython/TS1,47723.629.54.5%
duckdbSystemsC++69020.74.94.5%
phoenixFrameworkElixir1,42418.914.44.5%
redisSystemsC90514.38.94.0%
argo-cdGoGo1,88941.420.54.0%
arrowSystemsC++1,46628.312.43.8%
envoySystemsC++1,44446.415.73.5%
reactDynamicJS2,01017.531.13.4%
scala3ExpressiveScala 399512.612.93.3%
terraformGoGo2,22330.332.72.4%
grafanaGoGo/TS2,89316.324.61.9%
laravelFrameworkPHP4,44917.215.31.5%
ClickHouseSystemsC++2,56317.330.01.4%
railsFrameworkRuby6,51251.27.30.9%
kubernetesGoGo5,21742.519.90.8%
rustExpressiveRust7,91453.05.70.6%

Detail Pages

Rails Gravity Map
The Full Picture of a Multi-Architect Civilization
rails-gravity.html →
Laravel Gravity Map
Kingdom of the Creator
laravel-gravity.html →
esbuild Gravity Map
A Universe of One
esbuild-gravity.html →
React Evolution
A Decade of Generational Transition
react-evolution.html →