01
Map
Each track is four stages, from the fundamentals to the hard parts, in a deliberate order. Filter by depth, weight and fit to cut a track to what your next interview actually needs.
System design · low-level design · core CS · 3 tracks · 54 modules · 343 lessons
Learn how real systems fit together.
System design, low-level design and the core CS underneath, as three mapped tracks. Every lesson follows the same anatomy and every module ends with a drill that makes you reason out loud. No flames, no XP. Just the trade-offs senior engineers actually make.
Tracks
Three tracks. One anatomy.
System Design for how services fit together, Low-Level Design for the code inside them, Core CS for what runs underneath. Core CS is free in full; the other two open with a free Foundations stage. Every module closes with a drill.
How it works
Map it. Learn it. Drill it.
Every track is built for finishing, not browsing. Three loops, repeated across 54 modules.
02
Learn
Every lesson has the same anatomy: why it matters, the idea with a diagram, a trade-off table, how to say it in an interview, a quick check, takeaways. Ten to fifteen minutes each.
03
Drill
Each module closes with scenario prompts. Say your answer out loud, reveal the model answer, grade yourself. Items you mark for review wait for you on the dashboard.
Inside a track
System Design, end to end.
4 stages and 19 modules, in a deliberate order: each stage assumes the one before. Foundations is free; the rest is Pro. Low-Level Design follows the same shape, and Core CS is free in full.
- 01FoundationsFree
46 lessons · 5 drills
- 02Scaling
45 lessons · 5 drills
- 03Distribution
50 lessons · 5 drills
- 04Operating
26 lessons · 4 drills
Why Backplane
Built like the systems it teaches.
Opinionated structure, calm surfaces, and nothing that exists to make you tap more.
Depth, weight, fit
Plain words instead of star ratings. Filter to the cut of the track your next interview expects.
Diagrams as components
Every diagram is built from the same primitives in the design's own colours, so they read the same in both themes.
Prompt 3
Every hour on the hour the database CPU spikes for thirty seconds. Explain the mechanism and the fix.
Got itReview later
Drills that make you talk
Scenario prompts with model answers. Grade yourself honestly; review items come back on the dashboard.
51 / 163
Local-first progress
Start without an account. Sign in later and everything you did is merged, not lost.
Dark
Light
Two canvases, one accent
Black by default, light when you want it. One violet for the thing that matters right now.
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Typographic covers
No stock illustrations. Each cover is a line drawing of the concept itself: a hash ring, an LRU row, a two-phase commit. You recognise a lesson before you read its title.
Pricing
Free to start. One price for everything.
Core CS is free in full, and Foundations stays free in every other track, with no time limit. Pro unlocks the remaining stages and their drills.
Free
$0
All of Core CS and every Foundations stage, forever.
- The whole Core CS track: operating systems, networks, databases and OOP, with every drill
- The Foundations stage of System Design and of Low-Level Design
- Track map with search and filters
- Progress, bookmarks and drill grades, synced to your account
- Dark and light themes, reading controls
Pro
Everything$14
Every stage of every track, every drill, everything that ships next.
- All stages of System Design and Low-Level Design
- Every drill, including the interview playbook
- Blueprints: end-to-end designs in the 45-minute structure (coming)
- Ask about this lesson: a tutor scoped to what you are reading (coming)
- Early access to new modules
Start today
The first stage is free. The first lesson is eight minutes.
No account needed to begin. Sign in later and your progress comes with you.