Interview prep notes
HelpMePrep
My notes for system design, low-level design, and DSA interviews. Read in order when a topic is new. Jump to a worked problem when drilling.
Mercor
Software Engineer, Agents. 45-minute system design, a 60-minute coding block plus 30-minute review, and a 30-minute algorithms discussion. Each session is scored by a different engineer.
DoorDash
Software Engineer. Not a LeetCode round. A service-shaped coding problem, then a live build from an empty directory with an AI assistant, then a behavioral conversation with an EM.
Tracks
System design
A 45-minute delivery clock, the concepts and technologies interviews actually probe, reusable patterns, and worked problems from URL shortener through agent eval.
Low-level design
Object APIs and concurrency. The first worked problem is a TTL cache with LRU eviction.
DSA
Timed coding drills in C++. A standard-library toolkit, then a four-part dependency resolver.
How to use this
- For a 45-minute design round, learn the delivery clock first, then one worked problem out loud with a drawing tool and a visible timer.
- Mark a page complete when you can teach it without notes. Quiz scores stay in this browser.
- Company tabs are prep plans for specific loops.
- Search is full-text across the notes. Dark mode and progress survive reloads on this machine only.
Nothing here is synced to a server.