# Martijn de Kuijper

> Martijn de Kuijper is a seed investor at X (formerly Twitter) backing Software. See 2 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [X (formerly Twitter)](https://shizune.co/investors/profile/twitter)
- Location: Amsterdam, The Netherlands
- Total investments: 2
- Last investment: Jan 2022
- Lead investor: 0%
- Last updated: Aug 2026
- LinkedIn: http://www.linkedin.com/in/martijndekuijper
- X (Twitter): http://twitter.com/mdekuijper
- Website: http://www.qash.nl
- Facebook: http://www.facebook.com/martijndekuijper

Martijn de Kuijper is a seed investor at X (formerly Twitter) in Amsterdam focused on Software and Service Industry. Martijn de Kuijper was the Co-Founder of Revue. He currently serves as the Senior Product Manager of Twitter.

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Software | 1 | 50% |
| Service Industry | 1 | 50% |
| Information Technology | 1 | 50% |

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 1 | 50% |
| Pre-Seed | 1 | 50% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| GsmBD.co | Rise is a next-generation calendar that helps you make time for the things that matter most. | $3M | Seed | Jan 18, 2022 |  |
| Rise | Find time for what’s important | $3M | Pre-Seed | Jan 18, 2021 |  |

2 of 2 investments shown.

## Co-investors
- [Kersvers](https://shizune.co/investors/profile/kersvers-46ec) — VC Fund, 2 deals together

## About X (formerly Twitter)

VC Fund · San Francisco, United States

X, formerly Twitter, is a global social networking platform that allows its users to send and read 280-character messages. It enables registered users to read and post their tweets through the web, short message service (SMS), and mobile applications. As a global real-time communications platform, X has more than 400 million monthly visitors and255 million monthly active users around the world. X’s active group of registered members includes World leaders, major athletes, star performers, news organizations, and entertainment outlets. It is currently available in more than 35 languages. X was launched in 2006 by Jack Dorsey, Evan Williams, Biz Stone, and Noah Glass. X is headquartered in San Francisco, California, USA, with local offices in Atlanta, Austin, Boston, Boulder, Chicago, Detroit, Los Angeles, New York, Sunnyvale, and Washington. X's international offices are located in Amsterdam, Berlin, Dublin, London, Madrid, Paris, Rio de Janeiro, Sao Paulo, Singapore, Sydney, Seoul, Tokyo, Toronto, and Vancouver.

5 contacts available at X (formerly Twitter).

| Name | Title | Profile |
| --- | --- | --- |
| David Shackleton | Product Head at OpenBack Integration | https://shizune.co/investors/profile/david-shackleton |
| Kayvon Beykpour | Head of Consumer Product | https://shizune.co/investors/profile/kayvon-beykpour |
| Linda Yaccarino | Chief Executive Officer | https://shizune.co/investors/profile/linda-yaccarino |
| Martijn de Kuijper | Senior Product Manager | https://shizune.co/investors/profile/martijn-de-kuijper |
| Ryan Merl | Senior Software Engineer | https://shizune.co/investors/profile/ryan-merl |

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### Similar stage
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## FAQ

### What does Martijn de Kuijper invest in?

Martijn de Kuijper invests primarily in Software, Service Industry and Information Technology startups, most often at Seed and Pre-Seed stage. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### When did Martijn de Kuijper last invest?

The most recent investment recorded for Martijn de Kuijper closed in Jan 2022. Shizune tracks 2 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.

### Is Shizune's investor data accurate?

Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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