Technology Fundamentals 2 Explained Without the Jargon

Release Process: Serving static bytes is the cheapest thing you can do at the edge. Release Process: A schema is an interface; changing it is a migration, not an edit. Release Process: Track the denominator as carefully as the numerator.

Configurations should be reviewable in a diff, not only in a console. This is most visible in access control. Consider access control specifically. The best time to add an index is before the table gets large. Access Control: Failures are usually correlated, so plan for the shared dependency.

Load Balancing: The first thing to settle is the failure mode, not the happy path. Load Balancing: Measurements taken once are anecdotes; you need a baseline that repeats. Load Balancing: Costs usually concentrate in a small number of operations, so find those first.

Observability: If a metric has no owner, it will drift until it causes an incident. Observability: The cheapest optimisation is usually removing work nobody asked for. Observability: Aggregating at write time trades flexibility for predictable read cost.

For load balancing, the constraint matters more than the feature list. Periodic jobs should be safe to run twice, because they will be. Teams working on load balancing usually discover this the hard way. You rarely need a new component to fix a boundary problem. The signal you want is often already logged, just not aggregated. This is most visible in load balancing.

Consent also depends on capacity: a person must be able to understand the choice and communicate it. Alcohol or other drugs can affect judgment and awareness, and the effect differs from person to person. If someone seems confused, unconscious or too impaired to make or communicate a decision, do not proceed. Laws define capacity and consent differently across countries, so local legal guidance matters.

Schema Migration: A design that cannot be rolled back is a design that cannot be changed safely. Schema Migration: Latency budgets are easier to defend when every hop has a stated ceiling. Schema Migration: Caching helps only until the invalidation rules become the bottleneck.

A clinician or sexual-health service will usually ask about recent partners, types of sexual contact, contraception, previous STIs and any known exposure. These questions help identify which infections to test for and which body sites to sample. A person can ask why a question is relevant, decline to answer, or request a private conversation. The purpose is to guide care, not to assess or judge someone’s choices.

In practice, monitoring alerts behaves differently: Configurations should be reviewable in a diff, not only in a console. The best time to add an index is before the table gets large. The same reasoning holds for monitoring alerts. For monitoring alerts, the constraint matters more than the feature list. Failures are usually correlated, so plan for the shared dependency.

For rate limiting, the constraint matters more than the feature list. Configurations should be reviewable in a diff, not only in a console. Teams working on rate limiting usually discover this the hard way. The best time to add an index is before the table gets large. Failures are usually correlated, so plan for the shared dependency. This is most visible in rate limiting.

For content delivery, the constraint matters more than the feature list. A queue smooths spikes but also hides how far behind you are. Teams working on content delivery usually discover this the hard way. Retries without jitter turn a small outage into a large one. Separating the reads from the writes buys room to change either side. This is most visible in content delivery.

Search Indexing: A design that cannot be rolled back is a design that cannot be changed safely. Search Indexing: Latency budgets are easier to defend when every hop has a stated ceiling. Search Indexing: Caching helps only until the invalidation rules become the bottleneck.

API Design: You can often replace a coordination problem with an idempotency key. API Design: Anything that grows without a bound will eventually hit one. API Design: Documentation that is not tested tends to describe the previous version.

Configurations should be reviewable in a diff, not only in a console. This is most visible in schema migration. Consider schema migration specifically. The best time to add an index is before the table gets large. Schema Migration: Failures are usually correlated, so plan for the shared dependency.

In practice, search indexing behaves differently: Periodic jobs should be safe to run twice, because they will be. You rarely need a new component to fix a boundary problem. The same reasoning holds for search indexing. For search indexing, the constraint matters more than the feature list. The signal you want is often already logged, just not aggregated.

Queue Design: The first thing to settle is the failure mode, not the happy path. Queue Design: Measurements taken once are anecdotes; you need a baseline that repeats. Queue Design: Costs usually concentrate in a small number of operations, so find those first.

Screening is designed for people who may have an infection without knowing it; many STIs cause no noticeable symptoms. If someone has symptoms or has been told they may have been exposed, that is different from routine screening and should be discussed with a clinician. A screening appointment may need to include an assessment beyond the tests usually offered to someone without symptoms.

Cloud Infrastructure: Configurations should be reviewable in a diff, not only in a console. Cloud Infrastructure: The best time to add an index is before the table gets large. Cloud Infrastructure: Failures are usually correlated, so plan for the shared dependency.

If the rollback plan needs a meeting, it is not a rollback plan. That applies to edge caching as well. In practice, edge caching behaves differently: Small pages that stay small are easier to keep fast than large ones made fast. Write the invariant down; otherwise it lives only in someone's memory. The same reasoning holds for edge caching.

Consider access control specifically. A design that cannot be rolled back is a design that cannot be changed safely. Access Control: Latency budgets are easier to defend when every hop has a stated ceiling. Caching helps only until the invalidation rules become the bottleneck. That applies to access control as well.

Teams working on monitoring alerts usually discover this the hard way. If the rollback plan needs a meeting, it is not a rollback plan. Small pages that stay small are easier to keep fast than large ones made fast. This is most visible in monitoring alerts. Consider monitoring alerts specifically. Write the invariant down; otherwise it lives only in someone's memory.

Teams working on crawl budget usually discover this the hard way. You can often replace a coordination problem with an idempotency key. Anything that grows without a bound will eventually hit one. This is most visible in crawl budget. Consider crawl budget specifically. Documentation that is not tested tends to describe the previous version.

Cost Controls: The interesting number is not the average, it is the 99th percentile. Cost Controls: Adding a cache in front of a slow query is a fix; fixing the query is a cure. Cost Controls: Every abstraction you add is a place where behaviour can differ from intent.

Crawl Budget: Periodic jobs should be safe to run twice, because they will be. Crawl Budget: You rarely need a new component to fix a boundary problem. Crawl Budget: The signal you want is often already logged, just not aggregated.