Judgement Under Uncertainty
Choosing the best worst case when information is missing.
4 to work through
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intermediate Multiple choice
Zoom's daily meeting participants went from roughly 10 million in December 2019 to roughly 300 million by April 2020. No forecast produced that number. Which planning posture best survives a demand shift of that size?
2 min answer -
advanced
How do you decide when you have enough information to make an architectural decision?
2 min answer -
advanced
How should an architect make defensible decisions in a domain where the technology changes faster than the decision cycle?
2 min answer -
advanced
Review this decision record. It chooses a single Postgres primary over sharding for an orders service measured in production at 1200 writes per second, lists three rejected alternatives with reasons, and ends with "Revisit in 12 months". What would you change, what would you leave alone, and what one line makes the decision reviewable?
3 min answer
3 terms in this topic
Calibrated Confidence
Expressing certainty in proportion to actual evidence, so that stated confidence carries information rather than conveying personality.
practiceFalsification Trigger
A named signal and threshold written into a decision at the moment it is made, with an owner, so that telemetry rather than memory tells anyone wheth…
practiceReasoning Under Uncertainty
Making decisions with incomplete information — by classifying the uncertainty, buying information cheaply, and preferring reversible moves.
Neighbouring topics
Meta-Skills
General material on how architects think and work.
Systems Thinking
Interactions and feedback loops rather than isolated components.
Trade-off Analysis
Making costs explicit and comparable rather than asserting a preference.
First-Principles Reasoning
Reducing to physics, mathematics and economics, then reasoning up.
Failure Thinking
Asking of every box and arrow how it fails and how you would know.
Constraint Thinking
Designing for the budget, skills and regulations that actually exist.
Pattern Recognition
Seeing a familiar problem, and checking whether the forces match.
Pragmatism
The simplest architecture that meets the requirements usually wins.
Business Understanding
Connecting a design to the outcome that pays for it.
Influence Without Authority
Getting decisions adopted when you cannot mandate them.
Mentoring
Growing architectural judgement in other people.
Continuous Learning
Staying current without chasing every new thing.
Estimation
Sizing work and cost honestly, with the uncertainty stated.
Prioritisation
Choosing what not to do, and defending it.
Research & Evaluation
Assessing a technology quickly without adopting it by accident.
Handling Ambiguity
Making progress when the requirements are not yet knowable.
Technical Leadership
Setting direction and carrying accountability without a team reporting to you.
Ethics in Architecture
Privacy, accessibility, sustainability and the consequences of a design.
Career Development
Growing from senior engineer to architect and beyond.