Stewart Butterfield
Angel Investor
Vancouver, Canada
Stewart Butterfield is a Co-Founder at Slack.
- Total investments:
- 40
- Last investment:
- Lead investor:
- 0%
Last updated:
For AI agents: llms.txt
Industries Stewart Butterfield invests in
Stages Stewart Butterfield invests in
Countries Stewart Butterfield invests in
Round sizes
Contacts
| Type | Contact | Validation |
|---|---|---|
| Work email | ||
| Personal email | ||
| Work phone | ||
| Personal phone | ||
| Socials |
Round size
- Seed
- $50k–$29M
- Series A
- $3.4M–$75M
- Series B
- $2.6M–$100M
Investment Focus
Industry
- Software 12 (30%)
- Artificial Intelligence 8 (20%)
- SaaS 7 (18%)
- Internet 5 (13%)
- Information Technology 5 (13%)
Stage
- Series A 14 (35%)
- Seed 10 (25%)
- Series B 5 (13%)
- Angel 3 (8%)
- Series C 3 (8%)
Country
- United States 20 (50%)
- Canada 7 (18%)
- United Kingdom 3 (8%)
- Brazil 2 (5%)
- Sweden 1 (3%)
Investments
| Company | Description | Round | Links |
|---|---|---|---|
Centralize
|
Centralize is an IT firm that analyzes touch points with the help of tools and stakeholders for pre and post-sales teams. | $15M / Series A / Jul 29, 2026 | |
Viktor
|
Viktor is an AI‑driven platform that acts as a virtual coworker inside messaging and collaboration tools, connecting to a broad set of business‑software systems to automate workflows, run tasks, and support knowledge‑work operations across marketing, operations, and engineering functions. | $75M / Series A / May 19, 2026 | |
Beside
|
Beside is an app that provides users with a dedicated second phone number for calls and texts. It includes AI-driven voicemail transcription, call summaries, and actionable to-dos for conversations. It also supports integration with tools like CRM systems and automation platforms to sync call data and notes. | $20M / Series A / Oct 29, 2025 | |
Lovable
|
Lovable builds software that builds software. Lovable vision is to unlock human creativity by enabling anyone to create software. | $200M / Series A / Jul 17, 2025 | |
Unblocked
|
Unblocked is a continuous integration platform for mobile apps hosted in the cloud. Unblocked was developed as a result of difficult collective experiences spending long periods of time in meetings, putting up with interruptions, and sifting through dated documentation while developing software at businesses like Microsoft, Amazon, Meta, and Apple. | $20M / Series A / May 06, 2025 | |
Neo Financial
|
Neo Financial is a Canadian financial technology company that directly issues a range of Mastercard credit cards and offers CDIC-insured chequing and savings accounts through partnerships with regulated banks. To help Canadians improve their credit scores, Neo uniquely offers all its cards, including its premium ones, as secured cards. Beyond corebanking, Neo operates a proprietary rewards network of over 11,000 merchant partners, allowing users to earn cashback on everyday spending. | $79M / Series D / Nov 11, 2024 | |
Noded Ai
|
Noded Ai is preparing yourself for that customer meeting is tough. Noded brings them all together using your notes history and gives you exactly what you needed , when you need it. So you’re always prepared and one step ahead. | $4M / Seed / Jul 22, 2024 | |
|
Unblocked
|
Unblocked is a continuous integration platform for mobile apps hosted in the cloud. Unblocked was developed as a result of difficult collective experiences spending long periods of time in meetings, putting up with interruptions, and sifting through dated documentation while developing software at businesses like Microsoft, Amazon, Meta, and Apple. | $8.3M / Seed / Oct 03, 2023 | |
Unblocked
|
Unblocked is a context engine that gives AI coding agents the organizational knowledge behind your codebase: the decisions, discussions, and history scattered across GitHub, Slack, Jira, and Confluence. Agents with this context produce mergeable code on the first pass, burning fewer tokens on exploration and less developer time on review cycles andrework. | $8.2M / Seed / Oct 03, 2023 | |
Linear
|
Linear allows the user to manage software development and track bugs. Built for speed and efficiency.The founders started Linear from their own frustrations building software projects in successful high-growth companies like Airbnb, Coinbase and Uber. The founders wanted to create the tools that focus us and its team in making progress, not getin the way. Tools that are fast and efficient. Speed and performance were the main things Linear focuses on early on and keep focusing on that. | $35M / Series B / Sep 14, 2023 | |
| See all 40 investments → | |||
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FAQ
What does Stewart Butterfield invest in?
Stewart Butterfield invests primarily in Software, Artificial Intelligence and SaaS startups, most often at Series A and Seed stage. Most of the 40 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.
What is Stewart Butterfield's check size?
Stewart Butterfield typically joins rounds of $50k–$29M at Seed, $3.4M–$75M at Series A and $2.6M–$100M at Series B. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Stewart Butterfield participates in.
How do I contact Stewart Butterfield?
Public channels for Stewart Butterfield include LinkedIn, X (Twitter) and the website linked on this profile. 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 Stewart Butterfield last invest?
The most recent investment recorded for Stewart Butterfield closed in Jul 2026. Shizune tracks 40 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 Sep 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.
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