About me

Name: Daniel Lemire
Location: Montreal, Canada
Home page: http://lemire.me/en/
Research papers: Google Scholar profile, arXiv, DBLP

My work on bitmap indexes is used by companies like eBay, Facebook, LinkedIn and Netflix to accelerate their data processing. It is also part of platforms such as Apache Hive, Druid, Apache Spark, LinkedIn Pinot, Netflix Atlas and Apache Kylin. The version control system Git as used by GitHub is also accelerated by our compressed bitmaps. Some of my techniques have been adopted by Apache Lucene, the search engine behind sites such as Wikipedia or platforms such as Solr and Elastic. Some of my compression software is used by Apache Arrow and Apache Impala.

We wrote the fastest JSON parser in the world: simdjson. The simdjson library runs nearly everywhere and it is pioneering many new techniques.

I love to write: my blog has been featured on Reddit, Hacker News and Slashdot (1, 2).

I have written over 85 peer-reviewed papers. I am ranked in the top 2% of all scientists by citations (Stanford University/Elsevier ranking, 2024). I have held a research grant (NSERC) from the federal government for nearly 20 years. I was co-chair of the NSERC computer science committee in 2019-2020 and in 2020-2021.

I also have two sons and a beautiful wife. My dog had its own YouTube channel. I make my own bread, my own yogurt, my own beer, my own wine, my own port, my own furniture, my own drinks (I like daiquiris). I build robots, radio control sailboats and trucks. I grow my own vegetables in the summer using square gardening.

Talks

• Ada: Parsing Millions of URLs per Second (NodeConf EU 2023)
• Accurate and efficient software microbenchmarks (BID 2023)
• Unicode at gigabytes per second (SPIRE 2021)
• Parsing numbers at a gigabyte per second (MIT Fast Code Seminar 2021)
• Floating-point Number Parsing w/Perfect Accuracy at GB/sec (Go Systems Conf SF 2020)
• Data Engineering at the Speed of Your Disk (Performance Summit III 2020)
• Parsing JSON Really Quickly: Lessons Learned (QCon San Francisco 2019)
• Next Generation Indexes For Big Data Engineering (ODSC East 2018, Boston)
• Engineering Fast Indexes for Big Data Applications (Spark Summit East 2017, Boston)
• Engineering Fast Indexes for Big Data Applications (deep dive) (Spark Summit East 2017, Boston)
• Algorithms, how content finds ‘you’ (Discoverability Summit, Toronto, 2016)

Twitter-style bio

My 140-character bio:

Software performance expert. Among world’s top 2% scientists (Stanford University ranking, 2024). Among the 1000 most followed programmers in the world on GitHub.

Formal bio

When requested to provide a formal bio, I use this paragraph:

Daniel Lemire is a computer science professor at the Data Science Laboratory of the University of Quebec (TELUQ). He is ranked in the top 2% of all scientists (Stanford University/Elsevier ranking, 2024). He is among the 1000 most followed programmers in the world on GitHub; GitHub has over 100 million developers. He published over 85 peer-reviewed research papers. His work is found in many standard libraries (.NET, Rust, GCC/glibc++, LLVM/libc, Go, Node.js, etc.) and in the major Web browsers (Safari, Chrome, etc.). He is an editor at the journal Software: Practice and Experience (Wiley, established in 1971). In 2020, he received the University of Quebec’s 2020 Award of Excellence for Achievement in Research for his work on the acceleration of JSON parsing. His research interests include high-performance programming. He is @lemire on X, and he blogs weekly at https://lemire.me/blog

Odd facts about me

• I never memorized the multiplication tables. I never memorized the quadratic formula. I never memorized most trigonometric identities. I do not know my office door number or phone number. In general, I avoid memorizing facts, I prefer to write them down where I and others will find them. That is why I write so much.
• Up until 2017, I did not own a cell phone.
• I get lost easily. Even after living years at the same place, I still cannot locate the major streets by name. I got lost once or twice looking for my own office.
• I hear that people are sometimes nervous before addressing a crowd. I have no such stress: I am sure I could talk in front of tens of thousands of people without breaking a sweat. I will probably even tell jokes though it is unlikely many people will find me funny.
• I failed kindergarten and was put in a class for students with learning disabilities in first grade. When offered to rejoin a regular class, I chose to remain in the special class. Some of the reasons why they failed me in kindergarten was because I would not memorize my phone number and because I had trouble tying my shoe laces. I still walk with my shoe laces undone most of the time. I have never memorized my phone number. So I might still fail kindergarten.
• I lost all the electronic copies of my Ph.D. thesis the same day I sent the second revised version to the printer. Though I had backups, I overwrote all the backups with an empty file by accident. Had the school asked for a revision, I would have had to retype my thesis.
• Academically, I consider myself almost entirely self-taught. I am an autodidact with a Ph.D. Though I have been a tenured college professor in computer science for over a decade, with continuous research funding (in computer science) provided by the federal government through competitive grants, I have never taken a computer science class in college. I once attended a first-year computer college course for a couple of weeks, but I gave up quickly. I was once formally offered a job as a business professor at a good university, despite the fact that I never took a business class in college. I have three degrees in Mathematics (B.Sc., M.Sc., Ph.D.), but I derived very little use of all the classes I took. It should be said that I skipped class on every occasion.
• I have been programming computers since I was twelve. I still program most days. I read code all the time.
• I play video games almost daily. It is my favorite hobby. I tend to play games on a dedicated console.
• My house is filled with books. I am always surrounded by books.

Social networks

You can find me on Facebook, LinkedIn, GitHub, X.