Estimation
Sizing work and cost honestly, with the uncertainty stated.
5 to work through
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intermediate
An architect is asked how long a migration will take and has genuinely no basis for a number. How should estimation be approached so the answer is useful rather than either false precision or a refusal?
2 min answer -
intermediate
An architect is asked how long a migration will take and has genuinely no idea. What is the responsible answer?
2 min answer -
intermediate
An architect must estimate a large piece of work with genuine uncertainty. What makes an estimate useful rather than misleading?
2 min answer -
intermediate
You are asked how long a migration will take. You genuinely do not know within a factor of three. What do you say?
2 min answer -
advanced Multiple choice
Your capacity plan sizes the platform at twice last year's peak. Ticketmaster's November 2022 Eras Tour onsale took 3.5 billion system requests - four times its previous peak - after inviting 1.5 million verified fans. Which assumption inside a peak-multiple estimate fails first?
3 min answer
3 terms in this topic
Estimate Range With Narrowing Cost
Answering an estimation question with a range, the drivers of its width, and what it would cost to narrow it - which turns an estimation problem into…
practiceEstimation Range
Expressing an estimate as an interval with a stated confidence rather than as a single number, because a point estimate misrepresents what is known.
metricPeak Multiple
The factor by which a system is sized above its last observed peak - a fast planning heuristic that silently assumes the population generating load i…
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.
Judgement Under Uncertainty
Choosing the best worst case when information is missing.
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.
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.