What is heroku?
Heroku is a cloud platform that lets you run web applications without having to manage the underlying servers. You write code, push it to Heroku, and Heroku takes care of turning it into a live website or API.
Let's break it down
- Platform as a Service (PaaS): Heroku is a type of service where the hardware, operating system, and networking are handled for you.
- Git‑based deployment: You send your code to Heroku using Git commands (e.g.,
git push heroku main). - Dynos: These are lightweight containers that run your code. Each dyno is a virtual machine that can be started, stopped, or scaled.
- Add‑ons: Extra services like databases, caching, or monitoring that you can attach to your app with a single command.
- Buildpacks: Scripts that automatically detect your language (Node, Python, Ruby, etc.) and set up the environment needed to run your app.
Why does it matter?
- Speed: You can get a web app online in minutes instead of days spent configuring servers.
- Focus: Developers spend time writing features, not worrying about OS patches, firewalls, or load balancers.
- Scalability: Adding more dynos or upgrading a database is a few clicks or a command, letting your app grow with traffic.
- Cost‑effective for small projects: Free and low‑cost tiers let hobbyists and startups experiment without large upfront expenses.
Where is it used?
- Start‑up prototypes and MVPs (minimum viable products).
- Personal blogs, portfolios, and small business sites.
- Backend APIs for mobile or front‑end web apps.
- Educational projects and coding bootcamps because it’s easy to set up.
- Companies that need quick internal tools or micro‑services without managing infrastructure.
Good things about it
- Simple deployment workflow - push with Git, and it’s live.
- Managed environment - no need to patch OS or install system libraries manually.
- Extensive add‑on marketplace - one‑click integration for databases, email services, monitoring, etc.
- Automatic scaling - you can increase dyno count or switch to larger dyno types instantly.
- Supports many languages - Node.js, Python, Ruby, Java, Go, PHP, and more via buildpacks.
- Free tier - great for learning and small hobby projects.
Not-so-good things
- Cost can rise quickly when you need many dynos or high‑performance add‑ons.
- Limited control over low‑level server settings; custom configurations may be hard or impossible.
- Cold start latency on free or hobby dynos; the first request after inactivity can be slower.
- Vendor lock‑in - moving an app to another provider may require rewriting parts of the deployment pipeline.
- Dyno restarts happen daily, which can affect stateful applications if not designed for it.
- Performance ceiling - for very high‑traffic or compute‑intensive workloads, dedicated infrastructure may be more efficient.