Vilnius JUG Meetup #94

Talks (Event language - ENGLISH):

From Bugs to Brilliance: Testing Toolbox in Action - François Martin

What if I told you that there's an entire world of lesser-known, underutilized testing tools, libraries, and features waiting to elevate your testing game?

In this fast-paced, demo-driven session, we'll explore a selection of hidden gems that can make testing more effective and enjoyable. Focusing on Java and technology-independent tools, you'll discover practical additions to your testing toolbox that you can start using in your own projects.

Be warned, though: your testing toolbox might get a little heavier by the end of this talk!

The Spring Test Profiler: Cut Down Your Test Execution Time by 70% - Philip Riecks

AI writes your code in seconds. Then you wait twenty minutes for CI to tell you whether it works. The bottleneck has moved: writing code is cheap, but verifying it against a slow build is now what stands between you and fast feedback.

The biggest lever for faster Spring Boot builds is a hidden gem most teams barely use: Spring Test's context caching. Done right, your integration tests reuse expensive application contexts instead of starting fresh ones. Done wrong, every test class silently pays for a new context — and nobody notices until the pipeline takes an hour.

This talk introduces the Spring Test Profiler, an open-source tool that makes context caching visible. We'll start with the theory: how the cache works, what goes into the cache key, and why seemingly harmless choices — @MockitoBean, @DirtiesContext, dynamic properties — quietly multiply your build time. Then we get practical: using the profiler to spot cache misses and applying proven fixes, drawn from years of optimizing test suites across many teams, that cut build times by up to 70%.

We'll also cover the pitfalls: "optimizations" that break test isolation or hide flakiness. A fast build that lies to you is worse than a slow one.

Timeline:

18:30 Doors open, pizzas and networking

18:45 Welcome

18:50 "From Bugs to Brilliance: Testing Toolbox in Action" - François Martin

19:20 "The Spring Test Profiler: Cut Down Your Test Execution Time by 70%" - Philip Riecks