- AWS – CodeDeploy: Blue/Green and Where It Still Fits
CodeDeploy is the piece that takes a built artifact and puts it on the thing that runs it — and in 2026 it earns its place on EC2 and in ECS blue/green, not much elsewhere. The appspec file, the lifecycle hooks in the order they fire, and the validation hook that is the only reason blue/green is safer than in-place. Plus the automatic rollback alarm, and why a deployment can hang for an hour.
- LeetCode 347 – Top K Frequent Elements
The statement contains its own hint: better than O(n log n). That sentence exists to rule out sorting and a max-heap of everything — and the defence that there are usually few unique values is not a complexity argument. A min-heap capped at k works; bucket sort gets it to O(n), because frequencies are small bounded integers you can index by.
- MongoDB – Which Applications Actually Fit
Five shapes of application MongoDB suits well, and four where choosing it is a decision you will be undoing later.
- AWS – CodeCommit Is Closed. Here Is What to Use
On 25 July 2024 AWS stopped onboarding new customers to CodeCommit without announcing it. If you do not already have a repository there you cannot create one, and no new features are coming. What that means if you are on it — you can stay, and here is how to mirror out — and what to use instead: GitHub or GitLab, wired to CodePipeline or CodeBuild through a connection. Nobody should start here in 2026.
- MongoDB – Change Streams and Time-Series
Tail the oplog to push live updates to a browser, and see what a time-series collection measurably does and does not save.