About TierOnePrep

Most interview prep optimizes for algorithmic coding puzzles and treats every other round as an afterthought. The rounds that actually decide senior and staff offers — design in its several forms, and the behavioral round — are the hardest to practise realistically alone, because they need an interviewer to push back. TierOnePrep exists to make those practisable: questions modeled on the interview patterns FAANG and AI-first companies actually use, in a format that withholds the answer until you have done the thinking.

A modern loop is not one interview repeated. These are the rounds TierOnePrep prepares you for, each with its own format rather than one template stretched over all of them.

System design

Build a system from primitives and defend the capacity arithmetic behind it. Every guide carries back-of-envelope calculations as a first-class step.

Cloud architecture

The design round asked of cloud architects, solutions architects and platform engineers, assessed on service selection and migration sequencing rather than arithmetic. Each guide compares running a capability yourself against buying it managed, named across providers.

Low-level design

Also called object-oriented design, OOD or machine coding. Two kinds: designing the classes for a parking lot, an elevator or a chess game, and the operational version asked of SRE and DevOps engineers — pipelines, rollout and rollback, health checking, secrets, backups — which carries no code at all.

Coding

Attempt-first practice with a hint ladder before the solution, step-by-step visualizations for arrays, stacks, hash maps and binary trees, and full solutions in Python, C++, Java and Go.

Behavioral

Interactive guides that decode what the interviewer is actually scoring, then build a STAR answer structure with time budgets and pressure-test it with follow-ups. Answer structures, never canned scripts.

The discussion round

The broad questions with no system to draw — how would you reduce page load time, blue-green versus canary, what makes an architecture microservices. Free, and where cloud and infrastructure candidates are most often caught out.

Every question in the bank — 150+ of them, spanning 60+ interactive design walkthroughs and a large set of coding problems — is built by an engineer with more than a decade inside big tech infrastructure, and modeled on the interview patterns these companies use rather than copied from public question lists. The clarifying questions, the trade-offs and the follow-up grilling reflect how these interviews really run, including AI-infrastructure topics like LLM inference, GPU cluster scheduling and vector databases that increasingly come up at Anthropic, OpenAI and Nvidia. Candidates can also share a question they were asked; approved submissions are published without any name attached.

Every design guide runs the four phases a real interview follows: a deliberately vague Brief; a Clarify phase where you must ask the right questions before any solution is revealed; a Design phase with the architecture and its trade-offs; and Follow-ups rated by difficulty, with hints before answers. What sits inside the Design phase changes with the round — capacity calculations for system design, a managed-versus-self-run service comparison for cloud architecture, class skeletons for object-oriented design — because those are the artifacts each round is actually judged on. Coding questions invert the same idea: you attempt first, take hints one at a time, and the solution stays hidden until you ask for it.

23 questions are fully unlocked — complete solutions and walkthroughs, not previews — and need no account. So do the question of the day, every quiz, the discussion-round questions, the concepts library, the topic and role study paths, the estimation tools, and the written guides. You can work through a free question without signing up at all, and your progress follows you into an account if you make one later.

FAANG refers to Facebook (now Meta), Apple, Amazon, Netflix, and Google. The AI frontier — Anthropic, OpenAI, Nvidia, and SpaceX, alongside Meta and Google — is the newer tier of companies leading AI and space technology. TierOnePrep covers company-specific interview patterns across all of these, and the same patterns apply at Microsoft, Uber, Airbnb and anyone else running a FAANG-style loop.