Architecture Lab

Step-through diagrams of systems I've built in production — not textbook architectures, but the real flows, including the failure modes and the fixes they forced.

InteractiveSeat locking

Try to break the seat lock

Two phones, eight seats, one lock — and both phones are yours. Take the same seat twice, let a hold expire, pay with a dead token. Every rejection is a defense that exists in production for a reason.

Open the simulator →

Distributed Seat Locking

Exactly one winner per seat — enforced atomically, verified again at payment, and correct even when holds expire mid-flow.

8-step walkthrough

Wallet Transaction Flow

Money left the passenger and never reached the driver — the incident that turned a wallet into a ledger.

5-step walkthrough

Route Computation at 25% of the Bill

Every fare estimate was a paid API call. Cutting the bill by 75% meant asking a cheaper question, asking it less often, and still answering when the provider didn't.

5-step walkthrough

Driver Dispatch Under Timeouts

A search problem with a clock on it — expanding rings, batched offers, and a retry loop for when the answer is 'not yet' rather than 'no'.

8-step walkthrough