ENGINEERING LAB
Explore the trade-offs
Inspect the reasoning
Practical utilities and educational models for software engineers. Inputs stay in your browser. Examples are illustrative, and each tool explains its scope and limitations.
01 / Systems modeling
Architecture Trade-off Simulator
Build and compare system models. Inspect queueing, capacity, costs, and the assumptions behind every result.
Open tool
02 / API engineering
API Contract Inspector
Compare OpenAPI specifications and examine compatibility risks before changing an API.
Open tool
03 / Database performance
PostgreSQL Query Plan Explorer
Explore execution plans, compare estimates with actual statistics, and inspect potential bottlenecks.
Open tool
04 / Asynchronous systems
Asynchronous Task & Retry Simulator
Explore worker saturation, retries, backoff, idempotency, and dead-letter handling with reproducible simulations.
Open tool
05 / Software quality
Test Quality Lab
Run Python tests against realistic mutations and investigate which defects your tests miss.
Open tool
06 / Data integrity
Data Integrity Playground
Sign sample JSON with HMAC-SHA256, change the data, and verify what tamper detection can and cannot tell you.
Open toolUseful models need visible assumptions
Simulated outcomes are estimates under the model's inputs. They are not production benchmarks or evidence about an employer's internal systems.