Medium

Emily

Emily

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3h ago

Your Job Doesn’t Run at Google Scale. Your System Design Practice Still Can.

How to practice the follow up questions when your day job has never needed a million requests a second.

System design without big-tech experience, illustrated as a small system becoming a workload experiment

Emily

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23h ago

System Design Interview: You Rolled Back. Why Is It Still Broken?

Your old code may be perfectly healthy and completely unable to read what the new code left behind.

A rollback lever restores old code while an inbox still contains new-format data that the old reader cannot understand.

Emily

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1d ago

Backend Interview Question: Your API Takes 900 ms. SQL Takes 40.

Before adding a cache, build a request timeline and find the work your user is actually waiting for.

A large 900 ms API stopwatch contrasts with a 40 ms database query, asking where the remaining time went.

Emily

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2d ago

System Design Interview: Your 100-Request Limit Just Allowed 200

One boundary example, a small Python model, and a better way to explain what your rate limiter actually promises.

A clock boundary separates a configured limit of 100 from 200 accepted requests, introducing the rate-limiter interview exercise.

Emily

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2d ago

Backend Interview Question: Two Buyers Want the Last Seat. Who Gets It?

A small PostgreSQL example, a deliberately broken timeline, and the follow ups that turn a working demo into a defensible answer.

Two buyers see an available seat on their phones, while a single theatre seat A7 sits between them.

Emily

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3d ago

Before Your Next System Design Interview, Open These 3 Free Resources

Google, AWS, and PostgreSQL reading paired with small exercises that leave you with something better than another bookmark.

Three notebook cards introduce free system-design reading from Google, AWS, and PostgreSQL, focused on reliability, safe retries, and query plans.

Emily

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3d ago

System Design Interview: Your Queue Is Growing. Will More Workers Actually Help?

A small backlog calculation that makes scaling, downstream limits, and recovery time much easier to explain.

More workers feed the same narrow database gate, illustrating why worker count alone cannot remove a downstream bottleneck.

Emily

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4d ago

I Don’t Trust AI-Written Tests Until They Fail for the Right Reason

A small way to check whether your tests protect the requirement or simply agree with the code in front of them.

A developer inspects a green test report beside a boundary bug that the report missed.

Emily

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4d ago

SQL Interview Question: MAX(created_at) Doesn’t Return the Latest Order

Finding the newest timestamp is easy. Keeping the right row, handling ties, and putting the filter in the right place takes a little more…

A timestamp card and a full order receipt show why finding a maximum time does not identify the complete record.

Emily

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4d ago

Backend Interview Question: Why Does Page 2 Repeat an Order From Page 1?

One new order can break an apparently correct endpoint. Here is how to trace the bug, write a cursor query, and explain the guarantee…

Two pages contain order 104, showing a duplicate caused by a shifting pagination boundary.

Emily

Emily

Helping software engineers land high paying roles. Sharing tips, tricks and actionable steps to nail interviews in 2026.

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