# Marek Gumienny

> Marek Gumienny is a seed investor at Sharedband Limited backing Software. See 8 investments, check sizes, portfolio and contact details. Updated Aug 2026.

- Type: Angel Investor
- Fund: Sharedband Limited
- Location: London, United Kingdom
- Total investments: 8
- Last investment: Jun 2021
- Lead investor: 25%
- Last updated: Aug 2026
- LinkedIn: https://www.linkedin.com/in/marek-gumienny-57184b58

Marek Gumienny is a seed investor at Sharedband Limited in London focused on Software and SaaS. Marek Gumienny - Non Executive Director @ Sharedband Limited

## Contacts

5 contacts available for Marek Gumienny: work email, personal email, work phone, personal phone and socials. Sign up free to unlock them: https://app.shizune.co/sign-up/investor-profiles/find-email/marek-gumienny?utm_source=investor_profile

## Round sizes

| Stage | Round size |
| --- | --- |
| Angel | $637k–$1.2M |
| Series A | $2.3M–$16M |

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Software | 2 | 25% |
| SaaS | 1 | 13% |
| Privacy | 1 | 13% |
| Big Data | 1 | 13% |
| Consumer | 1 | 13% |

13 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 2 | 25% |
| Angel | 2 | 25% |
| Series A | 2 | 25% |
| Series B | 1 | 13% |
| Venture - Series Unknown | 1 | 13% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| MediSieve | MediSieve is a multi-award-winning medical device company developing Magnetic Blood Filtration (MBF), a platform technology for the treatment of blood-borne diseases by physically removing disease relevant targets directly from a patient’s bloodstream. MBF is an extracorporeal technology, similar to dialysis. A patient's blood is continuouslycirculated through an external blood loop containing the MediSieve system. Targeted magnetic particles (TB-MPs) are infused into the loop, binding specifically to disease-relevant targets in the patient's blood. The blood then flows through a magnetic filter which captures the particles and bound targets and the remainder of the blood returns to the patient unaffected; the TB-MPs never enter the patient’s body. MediSieve is based at the Imperial Incubator in White City, London. It has dedicated workshop and laboratory facilities (including capacity for ELISAs, Flow Cytometry and human blood testing) in which products are developed and validated. | $2.5M | Venture - Series Unknown | Jun 23, 2021 |  |
| Privitar | Privitar is an enterprise software company with a global client-base across North America, Europe, and Asia. The company is the development and adoption of privacy engineering technology enabling its customers to innovate and leverage data with an uncompromising approach to data privacy. Its software is designed to allow clients to analyzepotentially sensitive data while respecting customers’ privacy and confidentiality, resulting in the ability to leverage large, sensitive data sets while ensuring compliance with regulations (such as GDPR, CPRA and HIPAA) and ethical data principles.Privitar was founded in 2014 and is based in London, UK. |  | Series B | Jun 10, 2019 |  |
| MediSieve | MediSieve is a multi-award-winning medical device company developing Magnetic Blood Filtration (MBF), a platform technology for the treatment of blood-borne diseases by physically removing disease relevant targets directly from a patient’s bloodstream. MBF is an extracorporeal technology, similar to dialysis. A patient's blood is continuouslycirculated through an external blood loop containing the MediSieve system. Targeted magnetic particles (TB-MPs) are infused into the loop, binding specifically to disease-relevant targets in the patient's blood. The blood then flows through a magnetic filter which captures the particles and bound targets and the remainder of the blood returns to the patient unaffected; the TB-MPs never enter the patient’s body. MediSieve is based at the Imperial Incubator in White City, London. It has dedicated workshop and laboratory facilities (including capacity for ELISAs, Flow Cytometry and human blood testing) in which products are developed and validated. | $2.3M | Series A | Jun 04, 2018 |  |
| Privitar | Privitar is an enterprise software company with a global client-base across North America, Europe, and Asia. The company is the development and adoption of privacy engineering technology enabling its customers to innovate and leverage data with an uncompromising approach to data privacy. Its software is designed to allow clients to analyzepotentially sensitive data while respecting customers’ privacy and confidentiality, resulting in the ability to leverage large, sensitive data sets while ensuring compliance with regulations (such as GDPR, CPRA and HIPAA) and ethical data principles.Privitar was founded in 2014 and is based in London, UK. | $16M | Series A | Jul 18, 2017 |  |
| StoryTerrace | Story Terrace helps people to capture their life story using professional writers, editors and software.Our offices in Los Angeles and London intelligently match customers with one of our 500 professional writers to create beautiful, full-colour books more affordably than ever before. Our focus is on American English, British English, and Dutch.We work with bilingual writers that can interview in many more languages. We are currently creating our first life story in a virtual reality environment. |  | Seed | Jul 01, 2017 |  |
| StoryTerrace | Story Terrace helps people to capture their life story using professional writers, editors and software.Our offices in Los Angeles and London intelligently match customers with one of our 500 professional writers to create beautiful, full-colour books more affordably than ever before. Our focus is on American English, British English, and Dutch.We work with bilingual writers that can interview in many more languages. We are currently creating our first life story in a virtual reality environment. | $637K | Angel | Oct 06, 2016 |  |
| Privitar | Privitar is an enterprise software company with a global client-base across North America, Europe, and Asia. The company is the development and adoption of privacy engineering technology enabling its customers to innovate and leverage data with an uncompromising approach to data privacy. Its software is designed to allow clients to analyzepotentially sensitive data while respecting customers’ privacy and confidentiality, resulting in the ability to leverage large, sensitive data sets while ensuring compliance with regulations (such as GDPR, CPRA and HIPAA) and ethical data principles.Privitar was founded in 2014 and is based in London, UK. | $3.8M | Seed | Aug 02, 2016 |  |
| Privitar | Privitar is an enterprise software company with a global client-base across North America, Europe, and Asia. The company is the development and adoption of privacy engineering technology enabling its customers to innovate and leverage data with an uncompromising approach to data privacy. Its software is designed to allow clients to analyzepotentially sensitive data while respecting customers’ privacy and confidentiality, resulting in the ability to leverage large, sensitive data sets while ensuring compliance with regulations (such as GDPR, CPRA and HIPAA) and ethical data principles.Privitar was founded in 2014 and is based in London, UK. | $1.2M | Angel | Jul 17, 2015 |  |

8 of 8 investments shown.

## Co-investors
- [IQ Capital](https://shizune.co/investors/profile/iq-capital-partners) — VC Fund, 3 deals together
- [Illuminate Financial](https://shizune.co/investors/profile/illuminate-financial) — VC Fund, 2 deals together
- [Partech](https://shizune.co/investors/profile/partech) — VC Fund, 2 deals together
- [Accel](https://shizune.co/investors/profile/accel) — VC Fund, 1 deal together
- [Salesforce Ventures](https://shizune.co/investors/profile/salesforce-ventures) — VC Fund, 1 deal together

## About Sharedband Limited

VC Fund



2 contacts available at Sharedband Limited.

| Name | Title | Profile |
| --- | --- | --- |
| John Yeomans | Director | — |
| Marek Gumienny | Non Executive Director | https://shizune.co/investors/profile/marek-gumienny |

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## FAQ

### What does Marek Gumienny invest in?

Marek Gumienny invests primarily in Software, SaaS and Privacy startups, most often at Seed and Angel stage. Most of the 8 investments tracked by Shizune back companies in United Kingdom. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### What is Marek Gumienny's check size?

Marek Gumienny typically joins rounds of $637k–$1.2M at Angel and $2.3M–$16M at Series A. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Marek Gumienny participates in.

### How do I contact Marek Gumienny?

Public channels for Marek Gumienny include LinkedIn. For a verified work email and phone number, create a free Shizune account — contact data is searched across 20+ sources and validated before delivery, so your outreach lands in the right inbox.

### When did Marek Gumienny last invest?

The most recent investment recorded for Marek Gumienny closed in Jun 2021. Shizune tracks 8 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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