Privacy

Last updated 28 October 2026

LemonLemon.app runs hackathons: registration, teams, a guided journey, submissions, mentors and jury scoring. LemonLemon.app is responsible for the personal data described here. Questions or requests: [email protected].

What we store

• Account: your email address and sign-in sessions. There are no passwords; you sign in with a one-time code sent by email.
• Sign-up lists: if you signed up for a hackathon on the organizers’ own sign-up site, they can give us your email address and first name, so that you can sign in here and we can remind you to. We stop reminding you when you’ve registered, and delete the list a week after final submission closes. To stop the reminders earlier, reply to one and ask the organizers to take you off the list.
• Email delivery: if an email to you bounces permanently or you mark one as spam, Mailgun tells us and we note it, so we stop sending you announcements and reminders. Organizers of your hackathon can see that note.
• Registration: name, country, and — if the hackathon asks for them — university or company and area of study or job title.
• Team work: your team, ideas, solution description, uploaded files, checklist ticks and a log of who changed what.
• Pitch videos: the video your team uploads. It shows the people in it, so it is personal data too.
• Mentors: the profile you fill in — photo, expertise, availability, links and, if you choose, your email.
• Organizers: the name and photo you set on your profile.
• Jury: the scores and flags you give.
• Chat: messages you write in the chat rooms, direct messages and groups; who is in each conversation and what you've read; people you block and messages you report. Mentors' “online now” status is worked out while they have the site open and isn't stored.
• Contact form: your name, email, organization and message.
• Technical: when you were last active, and your IP address for rate limiting and bot protection.

Why

To run the hackathon you signed up for: let you work with your team, let the jury judge submissions and let organizers run the event. We email you sign-in codes and messages about the hackathon. We don't sell your data, show ads or use tracking cookies. The only cookies keep you signed in.

Who can see it

• Your team sees your registration details and everything the team writes and uploads.
• Jurors assigned to your category see your team's submission, including the pitch video.
• The organizers of your hackathon see everything about its participants and teams, except private chat (below).
• Everyone in the hackathon sees mentor profiles.
• Everyone in chat sees the Everyone room. Mentors and organizers see the Mentors room; jurors and organizers see the Jury room. Direct messages and groups are seen only by the people in them. Organizers see a private message when someone reports it to them. In case of abuse, or a risk of it, the organizers and LemonLemon may read the messages involved, including direct messages and groups.

Services that process it for us

• HostUp (Sweden) — the server and database.
• Cloudflare — the network in front of the site, bot protection on the contact form, and file storage and backups (stored in the EU).
• Mailgun (EU region) — sending email (sign-in codes, announcements, reminders, unread-message notices) and telling us about bounces and spam reports. Chat message text is never emailed.
• Mux (USA, under the EU–US Data Privacy Framework) — storing and streaming pitch videos. Mux gets the video, anonymous ids and anonymous viewing statistics — no names or email addresses.

How long we keep it

Until you ask us to delete your account: email [email protected]. We then delete your account and personal details, including the chat messages you wrote. Chat messages are not deleted automatically after the event. A team's submission, including its pitch video, belongs to the whole team — tell us if you want something you appear in removed. Database backups are kept for up to 12 months, then deleted.

Your rights

You can ask for a copy of your data, have it corrected or deleted, or object to how we use it — email [email protected]. You can also complain to your data protection authority (in Sweden: IMY).