Software Engineering

We ship often

Shipping early is not enough. We also need to keep shipping tiny iterations daily instead of waiting months to ship something big.

Having a strong sense of urgency , and making hard decisions fast is how we enable that process. Our sprints only last 1 week and are quite short when compared to the rest of the industry - this is by... See more

Some important formatting rules available in this style guide:

• Use four spaces for code indentation


• Limit all lines to a maximum of 79 characters


• Avoid extraneous whitespace in certain situations (i.e., inside brackets, between trailing comma and close parenthesis, ...)

But remember: The formatting rules should make the code more readable. Sometimes,... See more

Whenever you write a log, it’s important you choose the correct log level.

I personally mostly use ERROR, WARNING, INFO, or DEBUG (yes there are a few more).

Log levels TLDR

• ERROR: Parts of the flow failed, we want to send alerts to our on-call for this failures.


• WARNING: Doesn’t necessarily point to a failure, but an unexpected behavior that should

... See more

Coz: Finding Code that Counts with Causal Profiling

by Charlie Curtsinger and Emery Berger

Coz is a profiler for native code (C/C++/Rust) that unlocks optimization opportunities missed by traditional profilers. Coz employs a novel technique called causal profiling that measures optimization potential. It predicts what the impact of optimizing code... See more

Loose Coupling and High Cohesion: How To Avoid Tight Coupling and Low Cohesion?

Cohesion is a measure of the number of relationships that parts of a component have with each other.

High cohesion means that : All of the parts that are needed to deliver the component's functionality are included in the component.

Coupling is a measure of the number of... See more

The complete Protobuf platform

Accelerate gRPC adoption with the Buf Schema Registry — built by the world's Protobuf experts.

Build & Deployments

Our build process starts by pushing changes to a repository on GitHub. When code is pushed to a repository through a pull request, it triggers a job to build the changes made to the branch and deploy them in isolation. This worklow happens interactively within the pull request, where the author has visibility of all steps.

Some... See more

Using feature flags

It's always a good idea to put new features behind a feature flag.

This contributes to a rollout strategy that can surface user feedback in a much more contained and safe environment.

When thinking about how to rollout a new feature to users, first think about your peers. Many of the Resend team members also use Resend on their... See more

Comments are helpful sometimes. But sometimes, they are just an indication of bad code.The proper use of comments is to compensate for our failure to express ourself in code [1].Whenever you have to add a comment in your code, ask yourself if it is really required or if you could instead put that into a new function and name the function so that it... See more