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Coding interview and system design courses

Two courses sit under the company guides. Data Structures & Algorithms is for the coding rounds. System Design 101 is for the design round. Every guide assumes you know this material, so it pays to learn it first.

2 courses78 + 31 lessons103 practice problems

Which course to start with

It mostly comes down to the level you are interviewing for.

1
New grad
Mostly DS&A
2
Mid-level
DS&A, then design
3
Senior+
Design leads

New grad and intern

Start with DS&A and give it most of your time.

Coding rounds carry these loops. If a design question comes up at all, it is often a short chat about a small feature. It counts for far less than the coding rounds.

Mid-level

DS&A first, but don't skip design.

A mid-level loop often has several coding rounds and one design round, so coding still gets most of the weight. But a close result is often decided in the design round, and many mid-level candidates walk in with little practice.

Senior and above

Lead with system design, and keep your coding sharp.

The design round tends to count the most at this level. Strong coding rarely makes up for a weak design. You still get coding screens, though, and people do fail them.

Data Structures & Algorithms

This course teaches the patterns behind coding questions, so a new problem starts to look like one you have seen. Each pattern has its own lessons and visual walk-throughs. You practise on problems that run in the browser.

78 lessons103 practice problems68 visual explainers

What it covers

Start Data Structures & Algorithms

System Design 101

This course covers how large systems fit together and how to talk through one in an interview. It starts with what interviewers look for and how to run the round. Then it works through the building blocks and the tools you will use most.

31 lessons31 diagrams8 tools covered in depth

What it covers

The System Design Interview4 lessons

What Interviewers Actually Evaluate, The Delivery Framework, Requirements & Estimation, Communication & Whiteboarding

Fundamentals11 lessons

Networking Essentials, APIs & Protocols, Data Modeling, and 8 more in Premium

The Toolbox8 lessons

PostgreSQL, and 7 more in Premium

Scaling Playbook8 lessons

8 Premium lessons

Start System Design 101

Where the company guides come in

The courses cover what most companies have in common. A company guide covers how one company runs its loop, including the problems candidates report there.

Browse the 100+ company guidesSee 354 system design questions by company
Common questions

Should I learn data structures and algorithms or system design first?

It mostly depends on your level. New grads and interns should spend nearly all their time on data structures and algorithms, since coding rounds carry those loops. Senior candidates do better leading with system design, because that round tends to count the most. Mid-level sits in between. Algorithms come first, and design can tip a close call.

What is the difference between the two courses?

The data structures and algorithms course teaches the patterns behind coding questions. Once you know them, a problem you have not seen starts to look familiar, and you practise each one on problems that run in the browser. The system design course covers the parts large systems are made of, and how to put them together while someone watches you think.

Do these courses cover company-specific interviews?

No. They teach what most companies expect you to know already. The company guides add what is specific to one employer, like the problems candidates report there and what its interviewers tend to look for. Most people do the fundamentals first, then read the guide for the company they are interviewing with.