How property-based testing saves your system

Millions of test cases, zero manual effort - property-based testing makes it possible. Nikhil Barthwal shows you how to find bugs that no one would ever test. "The fundamental proposition of properties based testing is when the system gets too complicated, it is not possible for human to write every test cases." - Nikhil Barthwal Properties based testing is a method that checks constant output properties and complements traditional test strategies. This technique is particularly suitable for complex and microservices-based systems as it allows the appraisal of a wide range of inputs. Nikhil explains with several real life examples how PBT works, what the advantages are and where the method reaches its limits. 00:00:00 Welcome 00:02:48 Basics and examples 00:06:36 Components and application areas 00:11:27 Introduction to properties-based testing 00:12:50 Application of TLA+ with AWS 00:17:48 Limits and costs of properties-based testing 📌 Conference tip: TACON 2026 in Leipzig (September 16–17). I was there last year as a keynote speaker and really enjoyed the discussions 👉 [TACON](https://swt.fm/tacon) 🎯 Highlights: Property-based testing automatically generates test cases from a formal description of system behavior instead of writing each case manually because the number of possible fault combinations in distributed systems far exceeds human capacity. The three core components of the approach are generator, which generates test cases from the specification, verifier, which detects violations, and shrinker, which reduces a long error chain to the smallest reproducible step. Property-based testing reaches its limits when each generated test case incurs direct costs, such as phone calls or cloud resources, because with millions of automatically generated cases, expenses can get out of control. The concept started with the Haskell framework QuickCheck and has been ported to many languages; today, there are separate implementations for .NET, Python and other stacks, including commercial tools for safety-critical areas such as the automotive industry. The biggest hurdle when introducing property-based testing is not the technology, but the change in mentality within the team: gaining a single pilot team as a reference is more effective at convincing colleagues than any internal recommendation. 🔗 Links Blog Post for Episode: https://www.richard-seidl.com/en/podc... 🎙️ More from Richard Seidl Website: https://www.richard-seidl.com Linkedin:   / richardseidl   Podcast Software Testing: https://www.testing-unleashed.fm #softwaretesting #QA #propertybasedtesting