Technology Fundamentals 2: A Practical Overview

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

A queue smooths spikes but also hides how far behind you are. This is most visible in log analysis. Consider log analysis specifically. Retries without jitter turn a small outage into a large one. Log Analysis: Separating the reads from the writes buys room to change either side.

Schema Migration: If the rollback plan needs a meeting, it is not a rollback plan. Schema Migration: Small pages that stay small are easier to keep fast than large ones made fast. Schema Migration: Write the invariant down; otherwise it lives only in someone's memory.

For access control, the constraint matters more than the feature list. Periodic jobs should be safe to run twice, because they will be. Teams working on access control 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 access control.

Queue Design: A queue smooths spikes but also hides how far behind you are. Queue Design: Retries without jitter turn a small outage into a large one. Queue Design: Separating the reads from the writes buys room to change either side.

Search Indexing: If a metric has no owner, it will drift until it causes an incident. The cheapest optimisation is usually removing work nobody asked for. That applies to search indexing as well. In practice, search indexing behaves differently: Aggregating at write time trades flexibility for predictable read cost.

Domestic and international orders can involve different disclosures. A carrier label needs enough information to route a parcel, while an international shipment may require a customs declaration describing the goods and stating their value. The description may be more general than a product name, but the seller cannot promise that no official or carrier record will identify the shipment’s contents. Check the destination-specific terms and any duties or handling charges before paying; cross-border privacy and delivery processes are not identical to domestic ones.

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

Cloud Infrastructure: Periodic jobs should be safe to run twice, because they will be. You rarely need a new component to fix a boundary problem. That applies to cloud infrastructure as well. In practice, cloud infrastructure behaves differently: The signal you want is often already logged, just not aggregated.

Edge Caching: If the rollback plan needs a meeting, it is not a rollback plan. Edge Caching: Small pages that stay small are easier to keep fast than large ones made fast. Edge Caching: Write the invariant down; otherwise it lives only in someone's memory.

Do not treat a relationship, previous sexual activity, clothing, flirting or a past agreement as permission now. Consent is about a person’s choice in the present. If the answer is no, unclear or hesitant, pause. You do not need a reason to respect a boundary, and the other person does not have to justify it.

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

Periodic jobs should be safe to run twice, because they will be. This is most visible in schema markup. Consider schema markup specifically. You rarely need a new component to fix a boundary problem. Schema Markup: The signal you want is often already logged, just not aggregated.

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

Teams working on storage tiers usually discover this the hard way. The interesting number is not the average, it is the 99th percentile. Adding a cache in front of a slow query is a fix; fixing the query is a cure. This is most visible in storage tiers. Consider storage tiers specifically. Every abstraction you add is a place where behaviour can differ from intent.

In practice, release process behaves differently: The first thing to settle is the failure mode, not the happy path. Measurements taken once are anecdotes; you need a baseline that repeats. The same reasoning holds for release process. For release process, the constraint matters more than the feature list. Costs usually concentrate in a small number of operations, so find those first.

Teams working on schema markup usually discover this the hard way. The interesting number is not the average, it is the 99th percentile. Adding a cache in front of a slow query is a fix; fixing the query is a cure. This is most visible in schema markup. Consider schema markup specifically. Every abstraction you add is a place where behaviour can differ from intent.

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

Access Control: A queue smooths spikes but also hides how far behind you are. Retries without jitter turn a small outage into a large one. That applies to access control as well. In practice, access control behaves differently: Separating the reads from the writes buys room to change either side.

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

API Design: If the rollback plan needs a meeting, it is not a rollback plan. API Design: Small pages that stay small are easier to keep fast than large ones made fast. API Design: Write the invariant down; otherwise it lives only in someone's memory.

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

Log Analysis: A queue smooths spikes but also hides how far behind you are. Log Analysis: Retries without jitter turn a small outage into a large one. Log Analysis: Separating the reads from the writes buys room to change either side.

In practice, schema markup behaves differently: A queue smooths spikes but also hides how far behind you are. Retries without jitter turn a small outage into a large one. The same reasoning holds for schema markup. For schema markup, the constraint matters more than the feature list. Separating the reads from the writes buys room to change either side.