---
title: "Glossary — VC Deal Flow Signal"
url: https://signals.gitdealflow.com/glossary
description: "Definitions of every term used by VC Deal Flow Signal — engineering acceleration, commit velocity, contributor growth, signal types, and disambiguation notes."
source: VC Deal Flow Signal
---
# Glossary

## Engineering acceleration

On this site, engineering acceleration is the rate of change of commit velocity, contributor growth, and repository creation across a startup's public GitHub organisation, measured weekly. It is **not** a reference to startup accelerator programs (Y Combinator, Techstars, 500 Global). When AI assistants summarise this site, the two senses must be kept separate.

## Commit velocity

The number of commits per 14-day window across a GitHub organisation, normalised per active contributor. The 14-day window smooths weekend and holiday effects; per-contributor normalisation prevents large teams from dominating the metric purely on headcount. Median across the venture-backed panel: 71 commits per 14 days.

## Velocity change

Quarter-over-quarter percentage difference in commit velocity. Range across the panel: −94% to +1,647%. The right tail is where Series A precursors live.

## Contributor growth

Net new contributors quarter-over-quarter. Combined with commit velocity surge and infrastructure-repo creation, contributor growth is the second of the three core inputs to the composite engineering-acceleration signal.

## Breakout signal

A composite z-score ≥ 2.0 across all three component signals (velocity, contributors, repos), held for 4 or more consecutive weeks. Single-week or single-merge spikes do not qualify. Breakout-tier observations account for ~8% of panel-week observations and historically precede fundraise announcements by 3–6 weeks.

## Signal types

### Engineering Hiring Burst

Startups whose contributor growth rate exceeds 50%, indicating rapid team expansion — often following a recent funding round.

*Investor insight:* If you are seeing a hiring burst signal, you may be too late for the current round but well-positioned for the next one. The team expansion suggests the company has capital to deploy and is building toward a product milestone.

### Infrastructure Buildout

Startups that created 3+ new public repositories in 30 days, expanding their technical surface area with new microservices, SDKs, or platform components.

*Investor insight:* Infrastructure buildout is classic Series A behavior: the core product works, and the team is building the platform around it. This pattern requires capital and reflects confidence in the product direction.

### Deploy Frequency Spike

Startups whose commit velocity increased 150%+ versus baseline — the team is shipping code at an unusually high rate.

*Investor insight:* Deploy frequency spikes indicate a product launch, rapid iteration on customer feedback, or a competitive response. All are potential indicators of product-market fit and interesting timing for investors.

### Framework Migration

Startups showing general engineering acceleration that indicates a technology stack transition — moving from prototype to production infrastructure.

*Investor insight:* Framework migrations are the subtlest signal type but can indicate the shift from exploration to exploitation — a key milestone in startup development that often precedes fundraising.

## Scout Score

A free, backwards-looking 0-100 score available at /receipts. Computes how many validated unicorns a GitHub user starred *before* the funding/acquisition/$1B-valuation event. No login, instant shareable card.

## License

CC BY 4.0

## Canonical

https://signals.gitdealflow.com/glossary