Useful Mental Models For Product Engineers

Transcript

1. USEFUL MENTAL MODELS FOR PRODUCT ENGINEERS
2. MENTAL MODEL?
3. USING MODELS EVERY DAY
4. BUILDING A TOOLBOX
5. CONTAGION OF DESIGN DECISIONS 01 02 03 04 SECOND ORDER THINKING OPPORTUNITY COST COGNITIVE BIAS 05 IMPERMANENCE
6. CONTAGION OF DESIGN DECISIONS 01
7. —A TAXONOMY OF TECH DEBT “[Contagion:] If this tech debt is allowed to continue to exist, how much will it spread? That spreading can result from other systems interfacing with the afflicted system, from copy-pasting data built on top of the system, or from influencing the way other engineers will choose to implement new features.
8. Assumption: RRP - Discount Reality: RRP - (Discount - Delivery Fee) in DE/ES DB stored all three values on Car record Code copy-pasted across apps PLUS Data Reporting, outside of repo CALCULATING SAVING ON A CAR BEFORE AFTER Car record stores saving Data backfilled All consumers read that
9. Natural Contagion Examples (relative) - Database column / table names - high, used by analysts without context / access to code or docs, trickier to locate and change later • API / Communication Design between applications - high, consumers changes taken time, no ability to do one off release to fix • API / Communication Design within applications - medium, still tricky to fix between systems, but more malleable than between apps • … and so on ... • Individual methods - low- still aim for best practice (other factors like churn / readability), but contagion / cost of sub-optimal design far lower CONTAGION OF DESIGN DECISIONS
10. SECOND ORDER THINKING 02
11. First-order thinking is fast and easy. It happens when we look for something that only solves the immediate problem without considering the consequences. Second-order thinking is more deliberate. It is thinking in terms of interactions and time, understanding that despite our intentions our interventions often cause harm. Second order thinkers ask themselves the question “And then what?”
12. Time - what will this decision look like in 12 weeks, 12 months? Will this problem go away in time? Viability - Does an ad-hoc require external support, will you get it? Consumer facing change good for consumer or vice versa? Risk - Is a change first-order negative, but second-order positive? What is the max upside possible vs the max downside possible? Immediacy - can decisions be deferred if the future has too many unknowns? SECOND ORDER THINKING
13. —https://fs.blog/second-order-thinking/ “Failing to consider second- and third-order consequences is the cause of a lot of painfully bad decisions, and it is especially deadly when the first inferior option confirms your own biases. Never seize on the first available option, no matter how good it seems, before you’ve asked questions and explored.”
14. OPPORTUNITY COST 03
16. OKRs TI Initiatives One market / multi market plans OPPORTUNITY COST MEDIUM/LONG-TERM DAY TO DAY Which rabbit holes to pursue? How much scope should a task cover? Defer a decision till after the next task?
17. An individual has been described by a neighbor as follows: “Steve is very shy and withdrawn, invariably helpful but with very little interest in people or in the world of reality. A meek and tidy soul, he has a need for order and structure, and a passion for detail.” Is Steve more likely to be a) a librarian or b) a farmer? A QUESTION
18. COGNITIVE BIAS 04
19. —https://www.simplypsychology.org/cognitive-bias.html “A cognitive bias is a subconscious error in thinking that leads you to misinterpret information from the world around you, and affects the rationality and accuracy of decisions and judgments. Biases are unconscious and automatic processes designed to make decision-making quicker and more efficient.”
20. Answer is b) a farmer “Most people reply quickly that Steve is more likely to be a librarian than a farmer. This is surely because Steve resembles a librarian more than a farmer, and associative memory quickly creates a picture of Steve in our minds that is very librarian-like. What we do not think of in answering the question is that there are five times as many farmers as librarians in most countries, and that the ratio of male farmers to male librarians is even higher. The base rates simply do not come to mind and thus prevent an accurate computation and answer, namely that Steve is more likely to be a farmer” A QUESTION
21. PRIORITY A distortion that arises from the use of information which is most readily available, rather than that which is necessarily most representative. MASLOW’S HAMMER AVAILABILITY BIAS EMPATHY
22. “Confirmation bias refers to the tendency to interpret new information as confirmation of your preexisting beliefs and opinions.” - CONFIRMATION BIAS
23. “When individuals or groups in a study differ systematically from the population of interest leading to a systematic error in an association or outcome.” SELECTION BIAS
24. IMPERMANENCE 05
25. COST OF MAINTENANCE PLAN AND DON’T BLAME CODING PRACTICES
26. The map is not the territory All models are wrong, some are useful
27. • Farnham Street - https://fs.blog/mental-models/#building_a_latticework_of_mental_models • Taxonomy of Tech Debt https://technology.riotgames.com/news/taxonomy-tech-debt • Cognitive Bias - https://thedecisionlab.com/biases/ • Building an architecture to embrace rapid change https://www.lucagrulla.com/posts/evolutionary-architecture-and-microservices/ • Principles and Mental Models https://www.adamwaselnuk.com/principles-and-mental-models#discover-abstractions-instead-of-de signing-them RESOURCES