Skip to content


Migrating to Bazel Modules (a.k.a. Bzlmod) - The Easy Parts

You may be aware that Bazel will remove support for WORKSPACE in Bazel 9 in favor of Bazel Modules (a.k.a. Bzlmod). The current mainstream release is Bazel 7.2.0, so there's plenty of time to migrate. However, there's no time like the present to get started, to avoid further WORKSPACE dependencies and a pile of migration work in the future.

I recently completed the Bzlmod migration for EngFlow/example and our internal repos. This experience taught me a lot about Bzlmod and about migrating complex projects with challenging dependency issues that I'll share over a few blog posts. I'll also borrow from Sara's earlier post, in which she described an example bzlmod migration based on EngFlow's Bazel Invocation Analyzer repo.

The Many Caches of Bazel

As its "{fast, correct} — choose two" tagline promises, a major feature of Bazel is performance. Caching is a key technique Bazel uses to improve build speed. Bazel deploys several kinds and layers of caches. There are so many caches that it’s hard to keep them straight. Additionally, frequently used terms like “action cache” can be ambiguous. This blog post will lay out the major Bazel caching mechanisms.

Bazel Bites: A Tasty Metaphor for Streamlined Builds

When you search the internet for details about Bazel, you’ll likely come across something like this:

Bazel is a build system. It’s used to build and test software, converting source code into artifacts, such as executable programs.

Bazel’s headline, “{Fast, Correct} - Choose two,” emphasizes its focus on scalability and hermeticity. It’s language agnostic, allowing you to use Bazel to build projects written in a variety of different programming languages.

If this seems confusing or overwhelming at first, don’t worry – we’ve cooked up a different approach that could help. We’ve concocted this article using a slightly rare (yes, we went there!) cooking metaphor.

Bazel explained through cooking

Bazel explained through cooking

Supercharge Traditional CI/CD Pipelines and Cut Costs With EngFlow

At EngFlow, we've been dedicated to improving the speed, efficiency, and productivity of development processes for almost half a decade. As the market has evolved and FinOps gains more traction, we've expanded our focus beyond accelerating development to include optimizing costs and fostering sustainability in software engineering.

Let's discover how EngFlow can effectively help you achieve your goals by reducing infrastructure expenses and maximizing resource utilization.

Bazel scales more than just builds

Bazel creates a structured layer between the details of building and testing for individual languages and the users, both human and machine, that perform build operations. This abstraction simplifies workflows and is the foundation for powerful build-adjacent systems not possible with other build tools. Scalable Bazel builds underpin a scalable organization and development culture.

Bazel 7 is here - and Bazel Invocation Analyzer is ready for it!

On December 11th, 2023, Bazel 7.0 LTS was released, which includes multiple changes to improve build performance. More details below!

Bazel Invocation Analyzer (BIA) is an open-source tool by EngFlow that analyses the JSON trace profiles generated by Bazel and provides suggestions on how to improve the build performance. You can download the source and run the CLI or use the web UI available at

BIA has been updated to support the internal changes introduced with the launch of Bazel 7.0 LTS, so you can continue to speed up your builds with the help of BIA. It also features new types of suggestions to help you fine-tune your builds irrespective of whether you are using Bazel 7 already or not.

Bazel Community Day – Munich

On October 23 2023, the day before the first European BazelCon, EngFlow and Tweag organized the sixth Bazel Community Day at the Salesforce office, capped off with a happy hour sponsored by Gradle.

Photo from Bazel Community Day, Munich

Photo from Bazel Community Day, Munich

Secure Builds with Credential Helpers

Secure and reproducible builds are something we'd all like, and something many of us work on regularly.

One area that is frequently overlooked in the topic is how to securely provide credentials for external services used during a build. Systems often fall back to insecure methods like passing them on the command-line or storing them in plaintext on disk.

In this post, we will provide an overview of common authentication mechanisms and why they should not be considered secure, and then introduce Credential Helpers and how they do provide secure builds.

Coding in the Fast Lane with ibazel

The alternating sound of ctrl+s and ctrl+r followed by a deep sigh fill my days working on EngFlow's Build and Test UI. I mean, centering divs is already frustrating, but having to glance back and forth from one screen to another while refreshing the browser adds insult to injury. It doesn't help that being your average frontend dev I usually work with no less than a few thousand monitors. How else would I be able to look at the application, the code, and the ever present Flexbox layout cheatsheet at the same time?

Example of a minimal frontend dev's workstation

Example of a minimal frontend dev's workstation