Matthew Rocklin
I work in the Python data ecosystem, building tools like Dask and Coiled. I write about the technical and human aspects of this work.
- Posts
- 58 from 5 Sep 2022 to 25 Jun 2026
- Posting
- monthly (19 in the last year)
- Kind
- personal blog
- Feed
- https://matthewrocklin.com/feed_rss_created.xml
2026 17
- Frisky and Xarray Example
- Dictionaries v. Objects 2013-09-02 The mechanisms we choose to store and share data strongly impact the longevity of the code we write. When do we transition from dicts to custom classes?
- All Articles
- Updated Thoughts on AI
- Write Tests 2016-02-08 Testing feels like flossing—theoretically important. But if you contribute to long-term software with many collaborators, your tests will outlive your source code several times over.
- Stepping Back
- Biased Benchmarks 2017-03-09 Fair benchmarks are surprisingly difficult even with best intentions. We judge others by our objectives, fail to use their projects with expertise, and gravitate toward cases where we excel.
- Saying Goodbye to Winner-take-all Software
- Write Dumb Code 2018-01-27 We should write code that novice programmers can understand without explanation. After maintaining code, I think differently about showing off what I know.
- Claude Chic: Week 2
- Craft Minimal Bug Reports 2018-02-28 Maintainers' willingness to help you for free is optional. Minimal, complete, verifiable examples take 10-30 minutes but dramatically increase your chances of getting help.
- Multi-Agent Workflows
- Why I Avoid Slack 2019-02-28 Real-time chat makes everyone feel productive but does little for long-term consensus building. I prefer public, permanent, searchable, cross-referenceable discussions.
- Beginning Again
- Maintainers 2019-05-18 Best practices for open source maintenance: the difference between developers, reviewers, and maintainers, and how to spend your limited time well.
- Claude Chic
- Avoid Indirection 2019-06-23 Abstraction has costs. Every layer you add is another place readers have to look. Sometimes the clearest code is the most direct.
2025 12
- AI Zealotry
- Short Blogposts 2019-06-25 I encourage colleagues to write blogposts frequently. It informs your community, increases visibility, and focuses you on work relevant to others.
- Twitter, LinkedIn, and Failing in Public
- Senior Engineers 2019-11-09 My criteria for senior engineers: handle vague requirements, seek context, connect with stakeholders, take ownership, communicate regularly, handle uncertainty, and take vacations.
- I Walked across Spain
- Listen to sell 2019-12-05 Resist the urge to answer technical questions. We want to show off how things work, but we often dive too deep before understanding the customer's actual problem.
- Thoughtful Professional Writing
- Short attention span 2020-07-13 Speaking truth is easy. Getting people to listen is hard. Practical advice on respecting your reader through an attention span budget.
- Transactionalism vs Respect
- Ideal Tweet 2020-08-18 Start with a short single-line hook, then deliver actual novel content. People skim—get to the point immediately.
- Hammers and Nailguns
- Startup Metrics 2020-10-28 Hockey stick growth and GitHub stars sound great, but the reality is more nuanced. Dask took six years of listening and diligent community service.
2024 15
- Python Support is Socially Complex
- Tech Leads 2021-06-24 Tech leads steer efforts technically using soft power. It's a really fun role. Here are behaviors that make for a good one.
- Cloud Computing is Broken
- Small Scope Reviews 2022-03-26 A fast review cycle is incredibly valuable. Distinguish obligatory comments that stop regressions from commendable ones that add enhancements. Better is the enemy of good.
- Venting and Constructive Communication
- Revenue 2022-07-25 They care more about valuation than revenue, and only certain kinds of revenue matter. A taxonomy of good and bad revenue from selling open source software.
- SatCamp Retrospective
- SciPy Mission 2022-08-01 The SciPy community evolved from accelerating science, to enabling data understanding, to now—making people's lives more comfortable. The mission keeps growing.
- How I Almost Quit My Job, and How Being Selfish Saved Me
- Over Grown 2022-08-09 Painful, but we moved faster as a result. More smart people doesn't make you go faster. Often the opposite.
- What Does Pangeo 2.0 Look Like?
- User Valued Work 2022-08-24 Developer-valued work is valuable, but only in that it makes us faster at delivering user-valued work. Keep that distinction clear when prioritizing.
- Startup Advice 2022-09-05 Most advice is wrong—not because advisors are dumb, but because their experiences don't transfer. The wisest person for your situation is probably yourself.
- Failure 2022-09-05 Someone has to pay the psychological cost of uncertainty. I choose honesty, even when it has negative consequences.
- Offsites 2022-09-12 Remote teams accrue alignment debt and interpersonal friction. Offsites rapidly pay down that debt so everyone can go off and work independently again.
2023 7
- Stability Bias 2022-12-02 By not releasing due to regressions, we accept regressions in reverse. By not fixing confusing APIs, we confuse all future users. Stability has hidden costs.
- Meetings 2022-12-02 It made a huge difference. I learned that it's easy to spend energy on routine activities, think "I'm doing my job", and be completely wrong.
- Audio-Visual Setup 2022-12-18 How we present ourselves has unreasonable effectiveness on perception. An excellent Zoom setup costs $2000 and a day—anyone can achieve the unfair advantage that tall people have naturally.
- Think for yourself 2022-12-26 In dynamic environments, historical advice often doesn't apply. Imposter syndrome is appropriate—but so is trusting your own thinking.
- Rethinking My Website and Blog 2023-01-02 I felt smarter and happier pre-Twitter. I'm turning back to blogging—optimizing for longer attention spans and mixing evergreen with timely content.
- How I Conduct an Interview 2023-01-06 My approach to 45-minute interviews: what I share, what I ask, and how I evaluate candidates. Useful for interviewers or anyone interviewing with me.
- SaaS Go-to-Market 2023-02-01 A snapshot of where Coiled is on product and GTM, written for internal use but useful for other early-stage SaaS companies.
2022 7
- Performance Reviews 2023-02-14 Give critical feedback from voices other than your own. People are different—treat them differently based on need.
- Laser Eye Correction 2023-03-06 From deciding to explore the procedure to having my eyes lasered in two weeks. Long, rambling, and nothing to do with startups or tech.
- Reddit, Twitter, and LinkedIn Comparison 2023-11-10 I pushed the same message to Reddit, Twitter, LinkedIn, and Mastodon and tracked views and engagement. Reddit won by a mile.
- Decision Fatigue 2023-03-18 When you hit a roadblock, don't ask "what should we do?" Own the problem. Propose a solution. Help your team by carrying the weight yourself.
- Hiring Sales 2024-04-29 We fired the sales team when our product was bad. Now it's good. Finding the right early sales hire is an interesting challenge.
- Usage Based Pricing 2024-09-04 It was good for a while but became a dead end. The pros, cons, and alternatives for capturing value while making customers feel good about paying.
- How GitHub taught me to Micromanage 2024-05-11 Open source code review taught me to give intense, detailed feedback. Then I became a manager and learned why that doesn't always translate.