Master the first interview
A focused prep system for the low-level C / NIC datapath role — built around the real rounds, the actual hardware, and a wireless-PHY-to-networking pivot. Work top to bottom, or jump in from the sidebar.
The study path
Five moves, in order. Each links into a deeper section.
- First, know who they are and frame the move.The role & strategy— the team (Solarflare lineage), what they build, and the “same engineer, adjacent domain” pivot.
- Then walk the actual rounds you'll sit.First interview — recruiter → hiring-manager (CV deep-dive) → technical screen → the earn-the-vocabulary drills → behavioral → curveballs.
- Lock the one mechanism the whole role rests on.Ring buffers → NIC datapath (DMA, descriptors, doorbells) → where the microseconds go.
- Rebuild the intuitions that cause low-level bugs.Mental models — six interactive demos: memory reordering, false sharing, MMIO reads, cache locality, TCP congestion, all-reduce.
- Finally, drill until the answers are reflex.C questions and the senior bank (114 staff-level questions across 12 niches).
Everything on the site
The interview
🎯
First interview
Round-by-round playbook with say-it-out-loud answers, grounded in your CV.
🧭
The role & strategy
The team, what they build, the pivot narrative, and the manager round.
Core concepts
🔁
Ring buffers
The fundamentals + a live enqueue/dequeue demo and full C code.
🔌
NIC datapath
Descriptor rings, DMA, doorbells, and the lock-free SPSC queue.
⏱️
Latency demos
Toggle kernel-bypass / TX_PUSH / CTPIO and watch the nanoseconds drop.
🧠
Mental models
Six animations that fix the wrong intuitions behind low-level bugs.