🧪 Interactive Learning Tools
10 tools that make abstract concepts tangible. Stop reading. Start doing.
⌨️ Skill Drills
Build muscle memory with repetition
Vim Navigation Trainer
Navigate using hjkl only. Arrow keys disabled!
⌨️ Vim Navigation Trainer
Stars: 0Moves: 0
Arrow keys are DISABLED. Use only:
Binary & Hex Racer
Quick conversions between decimal, binary, hex.
🧮 Binary & Hex Racer
Score: 0Streak: 🔥 0
Convert between decimal, binary, and hex. 8 seconds per question!
10 → 1010 (bin)
255 → FF (hex)
Port Number Speed Run
Quick! What port is SSH? Race the clock.
⚡ Port Number Speed Run
Score: 0/0Streak: 🔥 0Best: 0
Learn common service ports! Pick the correct port for each service.
15 seconds per question. Use hints if you're stuck.
🔧 Builders
Construct solutions interactively
TCP Handshake Builder
Click packets in order to establish a connection.
🔌 TCP Handshake Builder
Click packets in the correct order to establish a TCP connection.
Regex Builder
Click blocks to build regex patterns for log parsing.
🔍 Regex Builder
Challenge 1/3Log line:
2024-01-15 10:30:45 [ERROR] Connection failed from 192.168.1.100🎯 Goal: Extract the date, time and IP address
Your regex pattern:
Click parts below to build your regex...
/(select parts below)/Available patterns:
chmod Calculator
Toggle permissions and see chmod update in real-time.
🔐 chmod Permission Calculator
Toggle permissions and see the chmod value update in real-time.
OCTAL
754
chmod 754 file.txt
SYMBOLIC
-rwxr-xr--
ls -l output
Owner= 7 (rwx)
Group= 5 (r-x)
Other= 4 (r--)
Quick presets:
🔬 Visualizers
Make the invisible visible
The Distance of Latency
If L1 cache is one foot away, RAM is miles.
🔬 The Distance of Latency
If L1 cache is 1 foot away, how far is RAM? Feel the difference.
On-die, per-core. Lightning fast.
Visual Scale (logarithmic)
Network (Datacenter)
~500μs
Network (Cross-Country)
~50ms
💡 In HFT, accessing RAM instead of L1 can cost you the trade.
Speed of Light Calculator
Physics sets the floor. See why microwave beats fiber.
🌍 Speed of Light Calculator
Physics sets the floor. How close can you get to it?
→
Distance
1,144 km
(710.848 miles)
⚡ Theoretical Min
3.82
ms (one-way)
Straight line, vacuum
📡 Microwave
4.21
ms (one-way)
Line-of-sight towers
🔌 Fiber Optic
8.01
ms (one-way)
Underground cables
💡 HFT Insight: Microwave saves ~7.60ms round-trip vs fiber. At $10M/day trading, that's worth millions in infrastructure.
🎮 Operator's Console
Simulate real-world scenarios
Order Book Replay
Watch a flash crash in slow motion.
📊 Order Book Replay: Flash Crash
ETH/USD
T+0s
T+0s: Normal Market
Healthy spread: $0.50. Deep liquidity on both sides.
Spread: $0.50 | Mid: $2000.25
Kernel Config Tuner
Toggle settings, watch your latency grade improve.
⚡ Kernel Config Tuner
Toggle settings and watch your latency score improve
🔧 CPU
isolcpus=2-7★ RECOMMENDED
Isolate CPU cores from scheduler. Dedicate to your app.
-15μs
nohz_full=2-7★ RECOMMENDED
Disable timer ticks on isolated cores. Less jitter.
-10μs
rcu_nocbs=2-7★ RECOMMENDED
Move RCU callbacks off isolated cores.
-5μs
intel_pstate=disable★ RECOMMENDED
Disable CPU frequency scaling. Lock to max.
-8μs
💾 Memory
transparent_hugepages=never★ RECOMMENDED
Disable THP. Prevents random latency spikes.
-12μs
numa_balancing=0★ RECOMMENDED
Disable NUMA balancing. Pin memory manually.
-6μs
vm.swappiness=0★ RECOMMENDED
Never swap. Keep everything in RAM.
-5μs
🌐 Network
busy_poll=50★ RECOMMENDED
Busy-poll sockets. Uses CPU but lowers latency.
-20μs
tcp_timestamps=0
Disable TCP timestamps. Small header savings.
-2μs
📋 Scheduler
Disable irqbalance★ RECOMMENDED
Manually pin IRQs. Prevent random migrations.
-8μs
Want to learn more?
These tools are embedded in the /learn curriculum. Each lesson has interactive components.
Explore /learn →