Backend Developer Roadmap
A step-by-step Backend Developer roadmap: the full stack, the skills to learn in order and the best places to learn each step.
The stack, end to end
- Fundamentals: HTTP and HTTPS, DNS, Browsers, Client and server, Git, GitHub, Branching and merging, Pull requests, Linux command line, File permissions, Processes, Shell scripting
- Backend: Node.js, npm, Asynchronous programming, Environment variables, Express.js, Routing and middleware, Validation, Error handling, REST API design, JSON, HTTP methods and status codes, API documentation, Authentication, JWT and sessions, Password hashing, OWASP Top 10, Input validation, Caching, Redis, Cache invalidation, System design, Scalability, Load balancing, Message queues
- Database: SQL, SELECT and WHERE, JOINs, GROUP BY and aggregates, INSERT, UPDATE, DELETE, MongoDB, Mongoose, Aggregation pipeline, Indexes, Data modelling
- DevOps: Docker, Dockerfile, Docker Compose, Container networking
- Get hired: Portfolio projects, Technical resume, Interview preparation
How the internet and the web work
Before writing code, understand what happens when you open a web page: browsers, servers, DNS, HTTP requests and responses, and what a URL is made of. Everything else you learn sits on top of this.
Skills
- HTTP and HTTPS
- DNS
- Browsers
- Client and server
Tips
- Open your browser developer tools, go to the Network tab and watch the requests a page makes.
Where to learn
- MDN: How the web works (docs, free)
- web.dev Learn (course, free)
- Cloudflare: Learning Center (docs, free)
Version control with Git and GitHub
Git records the history of your code and lets teams work on the same project. Learn to commit, branch, merge, resolve conflicts and open a pull request on GitHub. Almost every software job expects it.
Skills
- Git
- GitHub
- Branching and merging
- Pull requests
Tips
- Put every practice project on GitHub. It doubles as your portfolio.
Where to learn
- Pro Git book (book, free)
- GitHub Skills (practice, free)
Linux and the command line
Servers mostly run Linux. Learn to move around the file system, read and edit files, manage permissions and processes, and write small shell scripts.
Skills
- Linux command line
- File permissions
- Processes
- Shell scripting
Tips
- Use the terminal for everyday tasks for a few weeks and it will start to feel natural.
Where to learn
- Linux Journey (course, free)
- Bash reference manual (docs, free)
Node.js
Node.js runs JavaScript on the server. Learn modules, the file system, environment variables, asynchronous code, and building a server that talks to a database.
Skills
- Node.js
- npm
- Asynchronous programming
- Environment variables
Tips
- Keep secrets such as API keys in environment variables, never in code you commit.
Where to learn
- Node.js: Learn (docs, free)
- The Odin Project: NodeJS (course, free)
Express and building a web server
Express is the most common Node.js web framework. Learn routing, middleware, request validation, error handling and serving JSON to a frontend.
Skills
- Express.js
- Routing and middleware
- Validation
- Error handling
Tips
- Return the right HTTP status codes. Clear errors save hours of debugging.
Where to learn
- Express documentation (docs, free)
REST APIs
An API lets a frontend, a phone app or another system talk to your backend. Learn resources and HTTP methods, status codes, pagination, versioning and how to document an API. Add GraphQL later if you need it.
Skills
- REST API design
- JSON
- HTTP methods and status codes
- API documentation
Tips
- Test every endpoint with a tool such as Postman before building a frontend on it.
Where to learn
- Postman Learning Center (course, free)
- RESTful API tutorial (docs, free)
- GraphQL: Learn (docs, free)
SQL basics
SQL is how you ask a relational database questions. Learn SELECT, WHERE, ORDER BY, GROUP BY, aggregate functions, joins and how to create, insert, update and delete data.
Skills
- SQL
- SELECT and WHERE
- JOINs
- GROUP BY and aggregates
- INSERT, UPDATE, DELETE
Tips
- Practise on real-looking data. Write the query by hand before using any tool that writes it for you.
Where to learn
- SQLBolt (practice, free)
- SQLZoo (practice, free)
- Mode: SQL tutorial (course, free)
MongoDB and document databases
MongoDB stores flexible JSON-like documents. Learn collections, queries, indexes, the aggregation pipeline and how to model data when relations are not enforced for you.
Skills
- MongoDB
- Mongoose
- Aggregation pipeline
- Indexes
- Data modelling
Tips
- Design documents around how the app reads them, and remember that indexes matter just as much as in SQL.
Where to learn
- MongoDB University (course, free)
- MongoDB documentation (docs, free)
Authentication and web security
Learn how logins work (hashed passwords, sessions, tokens), how to restrict who can see what, and the common web attacks: injection, cross-site scripting and broken access control.
Skills
- Authentication
- JWT and sessions
- Password hashing
- OWASP Top 10
- Input validation
Tips
- Never store plain-text passwords, and never trust data coming from the browser.
Where to learn
- OWASP Top Ten (docs, free)
- PortSwigger Web Security Academy (practice, free)
Caching and Redis
Caching keeps frequently used data in fast memory so your app answers quicker and your database works less. Learn when to cache, how long, and how to avoid showing stale data.
Skills
- Caching
- Redis
- Cache invalidation
Tips
- Measure first. Cache only what is actually slow.
Where to learn
- Redis documentation (docs, free)
Docker and containers
A container packages an app with everything it needs so it runs the same everywhere. Learn images, containers, volumes, networks, Dockerfiles and Docker Compose.
Skills
- Docker
- Dockerfile
- Docker Compose
- Container networking
Tips
- Containerise one of your own projects end to end.
Where to learn
- Docker: Get started (docs, free)
- Play with Docker (practice, free)
System design basics
Learn how larger systems are put together: load balancers, caches, queues, databases and how to scale and keep them reliable. It also helps you explain your choices in interviews.
Skills
- System design
- Scalability
- Load balancing
- Message queues
Tips
- Practise explaining the design of a small system (a URL shortener) out loud.
Where to learn
- System Design Primer (book, free)
Build your portfolio, resume and interview skills
Employers want proof. Finish two or three projects you can show and explain, put them on GitHub, write a clear resume that matches the jobs you apply for, and practise the interview questions for the role.
Skills
- Portfolio projects
- Technical resume
- Interview preparation
Tips
- Describe what you built, why, and what you would improve. That is what interviewers ask about.
Build your resume · Check your resume (ATS) · Interview questions · Salaries · Browse jobs
Frequently asked questions
Where should I start with Backend Developer?
Start at step 1 and work down in order, because later steps build on earlier ones. If you are signed in, the roadmap compares your resume with each step and marks where you could start.
Do I need a degree to work as a Backend Developer?
It depends on the employer and the country. Many employers accept proven skills and projects, while others ask for a degree. Read the adverts for the roles you want and ask the employer if it is unclear.
How do I know I am ready to apply?
When you can build a small project from start to finish without copying a tutorial, and explain why you made your choices. Apply while you keep learning; you do not need to know everything.