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Mourjo Sen
@mourjo.me
53 followers 340 following 25 posts
✍️ mourjo.me/blog 💻 developing @bookingcom 💼 previously @stripe, @gojektech, @helpshift 🇫🇷 MS @inria
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Mourjo Sen @mourjo.me · Oct 9
I recently spoke at Tech Excellence meet-up about property based tests! Link below👇

www.youtube.com/live/8ONG4nJ...
Property Based Testing: Avoid Accidental Quality (Mourjo Sen)
YouTube video by Tech Excellence
www.youtube.com
mourjo.me
What you see is not all there is - unknown unknowns escape test cases because you can’t test what you don’t know.

Generative testing overcomes this cognitive bias by focusing on the fundamental properties of systems and not handcrafted examples.
Beyond Accidental Quality: Finding Hidden Bugs with Generative Testing
Generative testing uncovers hidden software bugs by exploring the input space and verifying system invariants. This surpasses example-based tests that rely on known scenarios and can miss edge cases.
www.infoq.com
November 4, 2025 at 3:27 PM
Reposted by Mourjo Sen
infoq.com
While Traditional Tests rely on handpicked examples, Generative Tests go further: they programmatically generate inputs, uncover unforeseen bugs, and offer broader coverage.

#GenerativeTesting reshapes how we think about #SoftwareQuality.

Read more: bit.ly/47jQT6i

#Testing #SoftwareDevelopment
November 3, 2025 at 7:47 AM
mourjo.me
I spoke at TechExcellence.io about accidental quality - why bugs get shipped even though tests pass.

www.youtube.com/live/8ONG4nJ...
Property Based Testing: Avoid Accidental Quality (Mourjo Sen)
YouTube video by Tech Excellence
www.youtube.com
October 17, 2025 at 11:43 AM
mourjo.me
I recently spoke at Tech Excellence meet-up about property based tests! Link below👇

www.youtube.com/live/8ONG4nJ...
Property Based Testing: Avoid Accidental Quality (Mourjo Sen)
YouTube video by Tech Excellence
www.youtube.com
October 9, 2025 at 2:31 PM
mourjo.me
I am speaking at API days Bangalore! Sign up with my code for a free ticket: I_KNOW_MOURJO_SEN

confengine.com/conferences/...
September 29, 2025 at 10:48 AM
Reposted by Mourjo Sen
jessitron.bsky.social
"We have to do the things [like documentation] that make human engineers better
before we can delegate to machines"
- Dave Williams
#o11yDaySF @honeycomb.io
September 11, 2025 at 7:27 PM
mourjo.me
I’m speaking at techsummit.io in a couple of weeks! 🥳🎉😁
September 2, 2025 at 8:55 AM
mourjo.me
Test cases only catch bugs if you know where they are. Paradoxically, it is ineffective for unknown unknowns.

Property-based tests don't ask you for examples - it generates them. You define the properties of your application, the system finds bugs.

github.com/mourjo/quick...
GitHub - mourjo/quick-meetings: A meeting scheduling application with bugs lurking in the dark that Property-Based Tests find!
A meeting scheduling application with bugs lurking in the dark that Property-Based Tests find! - mourjo/quick-meetings
github.com
August 29, 2025 at 4:23 PM
mourjo.me
In front of the majestic Alps, I felt tiny, insignificant but also very liberated.

They are impervious - whether I fail or succeed. Nothing I do will ever change the Alps. I suddenly didn’t feel afraid of failing, taking chances, experimenting.

Feeling tiny is liberating. Empowering. Unlimited.
July 25, 2025 at 7:23 AM
Reposted by Mourjo Sen
mourjo.me
What’s the difference between testing 🧪for bugs and searching 🔍 for bugs?

Property based tests search for unknown unknowns 🕵️ without relying on the programmer’s ability to enumerate test cases.

Hear more in my recent talk 👇
www.youtube.com/watch?v=5tCz...
Property Based Testing to Preseve Invariants - Fachtalk mit Mourjo Sen beim techCamp
YouTube video by intersoft GmbH
www.youtube.com
July 8, 2025 at 8:16 AM
mourjo.me
What’s the difference between testing 🧪for bugs and searching 🔍 for bugs?

Property based tests search for unknown unknowns 🕵️ without relying on the programmer’s ability to enumerate test cases.

Hear more in my recent talk 👇
www.youtube.com/watch?v=5tCz...
Property Based Testing to Preseve Invariants - Fachtalk mit Mourjo Sen beim techCamp
YouTube video by intersoft GmbH
www.youtube.com
July 8, 2025 at 8:16 AM
mourjo.me
My @infoq.com article won the second prize in the 2025 Article Contest, check it out!

www.linkedin.com/posts/infoq_...
#infoqarticlecontest #softwarearchitecture #infoqarticlecontest | InfoQ
🙌 Congratulations to Mourjo Sen, who won the second prize in the #InfoQArticleContest for his article, "Applying Flow Metrics to Design Resilient Microservices". You can read the article her...
www.linkedin.com
May 31, 2025 at 4:30 PM
mourjo.me
I presented a talk at Monster Scale 2025, video is out now

@scylladb.com #resilience #microservices #softwaredesign
Monster Scale Summit 2025 | What Flow Metrics Teaches Us by Mourjo Sen
YouTube video by ScyllaDB
www.youtube.com
March 30, 2025 at 12:01 PM
Reposted by Mourjo Sen
infoq.com
Software design with resilience embraces the reality that failure is inevitable!

We leverage #FlowMetrics (crucial for software delivery!) to measure & improve system resilience.

Dive into the #InfoQ article by @mourjo.me for deeper insights!

🔗 bit.ly/3Y5WMyJ

#Microservices #Performance #Metrics
March 27, 2025 at 4:59 PM
mourjo.me
Wrote an article on system agnostic resilience on @infoq.com check it out 👇
​​Applying Flow Metrics to Design Resilient Microservices
Software design with resilience is an acknowledgement to the reality that everything fails. We put metrics in place to help us detect and resolve such problems and failures. Flow metrics, commonly use...
www.infoq.com
March 26, 2025 at 9:49 AM
mourjo.me
The Internet helped create Adam Smith’s ideal marketplace, in which buyers and sellers find each other. The Internet did not replace people. It made them more efficient.

This is one of ten key ideas I took down from a memo Bill Gates wrote in 1999, all of which are still so relevant today:
A Look Back On Bill Gates' New Rules
This is article captures my notes and excerpts from Bill Gates’ 1999 article, New Rules, about how businesses should transform themselves in the new millennium.
mourjo.me
March 20, 2025 at 6:38 AM
mourjo.me
A team that is overworked does not perform well - nor does a server that is overloaded. What lessons can performant software supply chain teach us about microservice design?

I will speak about this topic at @scylladb.com Monster Scale Summit. Sign up today: www.scylladb.com/monster-scal...
March 1, 2025 at 1:02 PM
mourjo.me
I spent more hours learning in school but I learnt a lot more in college. A method I call "learning in sprints" combines the time-bounded structure of school education with the intuition and applicability of college education, and it works wonders.
Learning In Sprints
The last lecture finished by three in the afternoon. Yet on most days, I did not leave the St Xavier’s college campus until five – I recall spending two hours at the central library reading William St...
mourjo.me
February 25, 2025 at 6:51 AM
mourjo.me
A story about how I subconsciously started spending less time on my phone, how a privacy screen protector nudged me towards doing other – more productive – things than looking at reels on Youtube.
How A Screen Protector Increased My Productivity
“If you care about keeping your phone code secret, you should use this”, the seller said, emphatically pointing to the privacy screen guard. I knew about privacy-protecting screen guards, but I was no...
mourjo.me
February 13, 2025 at 6:09 AM
mourjo.me
My mental model of the how the corporate business works gets better as I speak to more people.

The best thing about this is, while I’m helping someone succeed I am really helping myself.

mourjo.me/blog/musings...
I Am Selfish - So I Want To Help You
I am a software engineer for ten years now. Over these years, I have worked with a number of people to help them navigate the landscape of the industry.
mourjo.me
January 31, 2025 at 12:18 PM
mourjo.me
The only reason I can't leave Twitter is because of the years of history I have with it -- like getting a retweet from Bruce Tate on a post I wrote. Sigh, on Twitter today, I just expect onlyfans accounts to react to my posts... I mean tweets.
January 24, 2025 at 4:08 PM
mourjo.me
@duckdb.org is a data engineering tool that is a must-have for software engineers. A data perspective is invaluable for a software engineer - from counting unique IDs in a CSV to parsing JSON logs to find failure patterns.

Here are three compelling reasons for us developers to start using DuckDB
Three reasons why developers should use DuckDB
Developers often have to analyse data, e.g. assessing the impact of an outage. DuckDB is a single tool for querying multiple data sources.
towardsdatascience.com
January 19, 2025 at 2:27 PM
mourjo.me
While at the surface writing does not seem to be a hard requirement of the software engineer’s job, structured thinking is. Writing helps convoluted, passing thoughts take a more permanent form, which my future self can come back to – ideas fleet, written artefacts remain.

mourjo.me/blog/musings...
Overcoming Barriers To Entry: Writing With Obsidian
“In ten years you’ll see me as a writer”. My 2008 yearbook would be disappointed in how things turned out. But it is the new year and it is never too late to start.
mourjo.me
January 13, 2025 at 8:50 AM