Who Goes Next: Heaps, Priority Queues, Timer Wheels and Schedulers

Deep End Era. Engineering with Sankalp · Oct 28, 2026 · 50m

In Toulouse, satellite flight-software engineer Siobhán Kelly tells new graduates why a lander on Mars kept rebooting in July 1997: the most important task was waiting on the least important one. In part seven of The Deep End's Data Structures series we build priority queues from scratch, store a tree in an array with no pointers, sift by ear, build Huffman codes with a heap, meet the Fibonacci heap that won on paper and lost in practice, fire millions of timers in constant time on Varghese and Lauck's wheels, and see how schedulers, from Linux's bitmap of lists to Pathfinder's VxWorks, turn…