
Matrix.org
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Gapmap.dev
interviewing.io
LeetCode
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Exercism
The interviewer will find your gaps in 45 minutes. Gapmap finds them first: a short conversation draws your personal map of topics, a 15-minute diagnostic measures your real level on each, and you close the gaps with study notes and mock interviews - in text or voice - graded like the real thing. 200+ topics at senior depth are free and open, no signup.
Matrix.org
Gapmap.devMatrix.org is recommended for individuals and organizations that prioritize privacy and security in their communications. It's ideal for tech-savvy users who value open-source solutions and those who seek to avoid centralized communication platforms. Additionally, it's suitable for developers looking to build custom communication solutions using a versatile protocol.
Gapmap.dev's answer:
Individual developers preparing for interviews - Gapmap is a personal tool, not a company subscription
Gapmap.dev's answer:
Most interview prep starts with practice. Gapmap starts with measurement: a short conversation about your goal draws a personal map of topics, and a 15-minute adaptive diagnostic scores your actual level on each one - so you only study what's actually weak. A topic counts as closed when you've explained it out loud to an AI interviewer that asks follow-up questions and grades your reasoning against per-question rubrics - not when you tick a checkbox.
Gapmap.dev's answer:
Mock-interview platforms and question banks answer "how do I practice?" but leave "what exactly should I practice?" to you. Gapmap answers that question first and keeps re-answering it: the map re-prioritizes after every graded answer. The entire study library - 200+ topics written to senior depth - is free with no signup; you pay only for measurement and mock interviews.
Gapmap.dev's answer:
Mid-level and senior software engineers preparing for technical interviews - frontend, backend, DevOps, system design - who have limited prep time and need to spend it on real gaps, not on rereading everything. It also fits engineers returning to the job market after years at one company who no longer know where they stand.
Gapmap.dev's answer:
Gapmap grew out of our own interview prep. The standard routine - reread everything, grind questions, hope - wastes most of its time on topics you already know. The tool we wanted didn't exist: something that would honestly tell you what you don't know, then check that you can actually explain it out loud. So we built the grading engine first, and the map grew around it.
Gapmap.dev's answer:
Next.js (App Router), TypeScript, Tailwind CSS, PostgreSQL (Supabase), Drizzle ORM, deployed on Vercel. The grading, interview and voice layer runs on Anthropic's Claude models.
Based on our record, Matrix.org seems to be more popular. It has been mentiond 597 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Technical implementation should include privacy controls as core features, not afterthoughts. Build data export functionality, implement secure deletion processes, and provide transparency reports showing what data you've collected and shared. Open-source privacy tools like Tor and Matrix provide excellent examples of privacy-first architecture design. - Source: dev.to / 4 months ago
Matrix is an open, decentralized communication protocol for real-time messaging, voice, and video. Synapse is the reference homeserver implementation -- the software you run to participate in the Matrix network. Think of it like email: you run your own server, but you can communicate with anyone on any other Matrix server worldwide. - Source: dev.to / 4 months ago
Matrix is the decentralized Slack of the future (or present really!). - Source: dev.to / 5 months ago
/me sighs; Merry Christmas everyone. For what it's worth, we've been working on improving Matrix's metadata footprint this year: MSC4362 (https://github.com/matrix-org/matrix-spec-proposals/blob/kaylendog/msc/simplified-encrypted-state/proposals/4362-simplified-encrypted-state.md) got implemented on matrix-js-sdk for encrypting room state (currently behind a labs flag on Element Web). Meanwhile more radical... - Source: Hacker News / 7 months ago
I think most of these are built using Matrix: https://matrix.org. They have connections with most providers like iMessage, FB, Instagram, etc. - Source: Hacker News / 11 months ago
Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.
interviewing.io - Free, anonymous technical interview practice
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
LeetCode - Practice and level up your development skills and prepare for technical interviews.
Telegram - Telegram is a messaging app with a focus on speed and security. Itโs superfast, simple and free.
Exponent - Interactive product management interview practice & coaching