# Aaron Janse

SWE @ AI startup | UC Berkeley 2024  
Cognition  
San Jose, California, United States

## At Cognition

- Role: Member of Technical Staff (Engineering)
- Joined: Feb 2026
- How they joined: Directly
- Before Cognition: Software Engineer, Jane Street
- Overlapped before Cognition with other Cognition people at: UC Berkeley; Jane Street (https://www.autumn.ai/resources/cognition/worked-together)

## Identity
- LinkedIn: https://www.linkedin.com/in/aaronjanse
- GitHub: https://github.com/aaronjanse
- Website: https://ajanse.me/
- Domain: cognition.ai

## Notes
- Credited publicly by Cognition's Matt Schrage as part of the cross-company team behind the Devin CLI, working with Nikhil Jha, @mcparadip, Dev Mchheda and @_seanyneutron 'on frontier agent harness and custom TUI rendering in Rust' alongside Silas Alberti's research team that trained SWE-1.6 Fast for the CLI. His earlier terminal multiplexer 3mux makes TUI rendering a natural fit. (https://x.com/MattSchrage/status/2054599783440925059)
- Created AsciiDots, an esoteric language based on ASCII art (about 1.2k stars); his site says it has been credited as inspiring several other languages, and he re-posted it to HN in Aug 2025 with an in-browser Pyodide playground. (https://ajanse.me/)
- Interned at Jane Street as a Software Engineer Intern in New York (May-Aug 2023) and returned full-time in Aug 2024. (https://www.linkedin.com/in/aaronjanse)
- Wrote 'Cross-compiling to Redox using Nix' on the Redox OS blog after nixpkgs merged PR #93568 enabling Nix cross-compilation to Redox; he built the redoxpkgs overlay. (https://www.redox-os.org/news/redox-plus-nix-0/)
- Created 3mux, a Go terminal multiplexer inspired by i3wm (about 1.9k GitHub stars); launched as 'Show HN: Terminal Multiplexer Inspired by I3' (108 points). (https://github.com/aaronjanse/3mux)
- Created DNS over Wikipedia, a Rust browser extension redirecting .idk domains via Wikipedia infoboxes (about 1.6k stars); its Show HN reached 398 points. (https://github.com/aaronjanse/dns-over-wikipedia)
- Public headline says "SWE @ AI startup | UC Berkeley 2024". (https://www.linkedin.com/in/aaronjanse)
- Started a technical Substack; inaugural post (May 31, 2026, during his Cognition tenure) covers using Marzullo's algorithm to sync lights to music in the DJ booth at house parties. (https://aaronjanse.substack.com/p/syncing-lights-with-music-marzullos)
- UC Berkeley BA in Computer Science, 2020-2024. (https://www.linkedin.com/in/aaronjanse)
- Quant Systems Intern at The D. E. Shaw Group in New York (May-Aug 2022). (https://www.linkedin.com/in/aaronjanse)
- Nix ecosystem contributor: member of the nix-community GitHub org, contributor to rnix (Rust Nix parser) and author of nix-eval-lsp, a Nix language server that evaluates code. (https://github.com/aaronjanse/nix-eval-lsp)
- Information Security Engineer Intern at LinkedIn in Sunnyvale (May-Aug 2021). (https://www.linkedin.com/in/aaronjanse)
- I discovered CVE-2020-28638, an encryption utility bug that silently encrypts some users' files with a hard-coded password. I'm experienced with Nix, a declarative package management and deployment system. I recently contributed code to allow cross-compiling packages to Redox, a new operating system. My first major contribution to open source was AsciiDots, an esoteric programming language. Since then, I've also created 3mux, a terminal multiplexer inspired by i3; this comes from the profile summary and preserves the person's own positioning. (https://www.linkedin.com/in/aaronjanse)
- Full-stack intern at forecasting platform Metaculus (Jan-Apr 2021). (https://www.linkedin.com/in/aaronjanse)
- Other open-source experiments include fhe-cpu (fully homomorphic CPU proof of concept), bootstrapOS (bootstrap an OS from machine code to web server) and marble-complete (Turing-complete marble runs in ASCII art). (https://github.com/aaronjanse?tab=repositories)
- Previous roles include Member of Technical Staff at Cognition; Software Engineer at Jane Street; Software Engineer Intern at Jane Street; Quant Systems Intern at The D. E. Shaw Group; Information Security Engineer Intern at LinkedIn; Intern, Full stack at Metaculus; Summer Intern at SiFive. (https://www.linkedin.com/in/aaronjanse)
- Education history includes Bachelor of Arts - BA, Computer Science, University of California, Berkeley. (https://www.linkedin.com/in/aaronjanse)
- Still actively pushing to his personal site repo aaronjanse.github.io as of Nov 2026. (https://github.com/aaronjanse)
- Location is San Jose, California, United States. (https://www.linkedin.com/in/aaronjanse)

## Experience
- Member of Technical Staff at Cognition (Feb 2026 - May 2026)
- Software Engineer at Jane Street - New York, New York, United States (Aug 2024 - Jan 2026)
- Software Engineer Intern at Jane Street - New York, New York, United States (May 2023 - Aug 2023)
- Quant Systems Intern at The D. E. Shaw Group - New York City Metropolitan Area (May 2022 - Aug 2022)
- Information Security Engineer Intern at LinkedIn - Sunnyvale, California, United States (May 2021 - Aug 2021)
- Intern, Full stack at Metaculus (Jan 2021 - Apr 2021): Metaculus is a forecasting technology platform that optimally aggregates quantitative predictions of future events.
- Summer Intern at SiFive (Jun 2018 - Aug 2020)

## Education
- University of California, Berkeley - Bachelor of Arts - BA, Computer Science - (Jan 2020 - Jan 2024)

## Sources
- https://www.linkedin.com/in/aaronjanse
- https://ajanse.me/
- https://github.com/aaronjanse
- https://www.redox-os.org/news/redox-plus-nix-0/
- https://x.com/MattSchrage/status/2054599783440925059
- https://aaronjanse.substack.com/p/syncing-lights-with-music-marzullos
- https://hn.algolia.com/api/v1/search?tags=author_aaronjanse&hitsPerPage=50
- https://api.github.com/users/aaronjanse/repos?per_page=100&sort=pushed
- https://github.com/aaronjanse/3mux
- https://github.com/aaronjanse/dns-over-wikipedia
- https://github.com/aaronjanse/nix-eval-lsp
- https://github.com/aaronjanse?tab=repositories
- https://www.minnesotaorchestra.org/about/our-people/orchestra-musicians/aaron-janse


Researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-04. Profile: https://www.autumn.ai/resources/cognition/people/aaron-janse · Everyone at Cognition: https://www.autumn.ai/resources/cognition/people