SymmetricalDataSecurity: A concise summary of software concepts

Test Driven Development (TDD)

Test, Code, Refactor https://en.wikipedia.org/wiki/Test-driven_development

Lean

Better than Free

https://kk.org/thetechnium/better-than-fre/

immediacy
personalization
interpretation/support
authenticity
accessibility
embodiment
patronage
findability

Persuasion

https://en.wikipedia.org/wiki/Robert_Cialdini

reciprocity
commitment/consistency
social proof
authority
liking
scarcity

Competition and Profit

https://en.wikipedia.org/wiki/Porter_five_forces_analysis

Threat of new competition (barriers to entry, customer loyalty, desirability of that industry/biz model)
Threat of substitute products or services (switching costs, quality, compatibility)
Bargaining power of customers (switching costs, market options, dependency for other services)
Bargaining power of suppliers (switching costs, supplier choice, supplier becoming competitor)
Intensity of competitive rivalry (innovation, branding, economies of scale)

Schelling's segregation model

Micromotives and macrobehavior , https://en.wikipedia.org/wiki/Thomas_Schelling#Models_of_segregation

Granovetter threshold model for peer effect on collective behavior and Strength of Weak Ties (aka how LinkedIn gets you a new job), https://en.wikipedia.org/wiki/Mark_Granovetter

Cognitive Biases

Bandwagon Effect (Groupthink)
Confirmation Bias: search for and interpret information and memories that support preconceptions
Gambler's Fallacy: future probabilities are affected by previous outcomes
Negativity Bias: paying more attention to bad news
Neglect of Probability: disregarding probabilities when making a decision (risk of flying versus driving)
Observational Selection Bias (Frequency Illusion): noting something previously ignored results in a misconception that it has increased in frequency
Projection Bias: wrongly presuming others think like us
Status Quo Bias: things should stay the same

Logical Fallacies and Disinformation

Appeal to probability: because something could happen it is inevitable that it will happen (see Gambler's Fallacy and Neglect of Probability)
Silence, Indignant, Rumors, Straw Man, Ad Hominem, Hit and Run, Question Motives, Invoke Authority, Play Dumb, "That's old news", Confess to a lesser item and "come clean", Enigma, Rube Goldberg Logic, Demand a complete solution, Fit the facts to alternate conclusions, Remove witnesses/evidence, Change the subject, Antagonize, Ignore proof and demand impossible proof, False evidence/facts, Loudly call for a separate investigation (ideally either biased or with confidential findings), Manufacture a new truth, Larger distractions, Silence critics, Lie low

note that these topics are often associated with paranoid conspiracy theories, "Rules of Disinformation"

Keys to being successful

lists
organize (categorize)
prioritize
schedule

brainstorm goals and feelings: "say what you're going to do and then do what you say"

Concentrate, Iterate, Automate, Validate, Appreciate

Software version: core tech strengths & problem, quick releases, automate, test!, style? + recognize the contributions
Military version: core strength and enemy weaknesses, rapid short executions, make excellence a reflex, check for brittleness, engender loyalty

7 habits of highly effective people

be proactive
"begin with the end in mind" (envision the goal)
"put first things first" (order and prioritize)
"think win-win" (good outcomes for everyone)
"Seek First to Understand, Then to be Understood" (listen, then persuade)
"synergize" (teamwork)
"sharpen the saw" (sustainable balance)

https://en.wikipedia.org/wiki/The_7_Habits_of_Highly_Effective_People

Maslow's Hierarchy of Needs

The lowest levels of the pyramid must be satisfied before people can focus and succeed at higher levels.

     Self-Actualization
    _______Esteem________
  _____Love/Belonging______
 __________Safety___________
_________Physiological_________

https://en.wikipedia.org/wiki/Maslow's_hierarchy_of_needs

Important Software Concepts

Do Not Repeat Yourself (DRY)
Model View Controller (MVC)
Atomic Consistent Isolation Durability (ACID)
Abstraction Polymorphism (overloading, inheritance, overriding interface) , Inheritance , Encapsulation
Consistency Availability Partition tolerance vs Basically Available Soft-State with Eventual consistency
Nondeterministic Polynomial ... NP-hard https://en.wikipedia.org/wiki/NP-hard
- co-NP (verifier of "no" answer")

https://en.wikipedia.org/wiki/Timeline_of_algorithms

Amdahl's Law

A system cannot be sped up by parallelization more than the inherently serial steps https://en.wikipedia.org/wiki/Amdahl%27s_law
- So benchmark your system, then determine what parts can be parallelized and how much that will improve the result and how much will it cost to do so

Conway's Law

The system design produced by an organization will reflect the organization's communication structure. https://www.melconway.com/Home/Conways_Law.html
- Commonly referred to when considering how adding a new person or new team to organization will affect productivity

Brooks' Law

Adding resources (people) later in a project will make it even later https://en.wikipedia.org/wiki/Brooks%27s_law
- A decent observation given the above "laws": if a task has serial parts adding people (parallelization) will not speed it up AND every person will have to interface

Moore's Law

Computing power will double (or become cheaper by half) every two years https://en.wikipedia.org/wiki/Moore%27s_law
- Sustained in part by improvements in complimentary technologies like Memory, Storage, Cooling, etc.
- At a certain point in the future potentially only possible using parallel computing but with an increased coordination cost (including software that leverages parellization)

Postel's Law

Be conservative in what you do, be liberal in what you accept from others

https://en.m.wikipedia.org/wiki/Robustness_principle

Laws of Unix

https://en.wikipedia.org/wiki/Unix_philosophy#Eric_Raymond.E2.80.99s_17_Unix_Rules

Modularity: Write simple parts connected by clean interfaces.
Clarity: Clarity is better than cleverness.
Composition: Design programs to be connected with other programs.
Separation: Separate policy from mechanism; separate interfaces from engines.
Simplicity: Design for simplicity; add complexity only where you must.
Parsimony: Write a big program only when it is clear by demonstration that nothing else will do.
Transparency: Design for visibility to make inspection and debugging easier.
Robustness: Robustness is the child of transparency and simplicity.
Representation: Fold knowledge into data, so program logic can be stupid and robust.
Least Surprise: In interface design, always do the least surprising thing.
Silence: When a program has nothing surprising to say, it should say nothing.
Repair: Repair what you can, but when you must fail, fail noisily and as soon as possible.
Economy: Programmer time is expensive; conserve it in preference to machine time.
Generation: Avoid hand-hacking; write programs to write programs when you can.
Optimization: Prototype before polishing. Get it working before you optimize it.
Diversity: Distrust all claims for one true way.
Extensibility: Design for the future, because it will be here sooner than you think. (Or, to put it another way, your creations will last longer than you think!)

Clean Code

Source Code is for humans, make it easy to read and understand
The code is the authoritative source (comments add context)
Leave the campground cleaner than you found it
Tests reveal what the code outputs; clean code runs all of the tests
Meaningful Names
Functions: A minimum number of parameters and the smaller the better
Open - Close principle
Single Responsibility (do one thing, and do it well)
No Duplication (DRY)
Objects allow modularity, Boundaries keep you sane
Separate Constructing a System from Using it (and Initialization from Runtime)

Fallacies of Distributed Computing

https://en.wikipedia.org/wiki/Fallacies_of_distributed_computing

The network is reliable.
Latency is zero.
Bandwidth is infinite.
The network is secure.
Topology doesn't change.
There is one administrator.
Transport cost is zero.
The network is homogeneous.

How Complex Systems Fail

http://web.mit.edu/2.75/resources/random/How%20Complex%20Systems%20Fail.pdf

Complex systems are intrinsically hazardous systems
Complex systems are heavily and successfully defended against failure
Catastrophe requires multiple failures – single point failures are not enough
Complex systems contain changing mixtures of failures latent within them
Complex systems run in degraded mode
Catastrophe is always just around the corner
Post-accident attribution accident to a ‘root cause’ is fundamentally wrong
Hindsight biases post-accident assessments of human performance
Human operators have dual roles: as producers & as defenders against failure
All practitioner actions are gambles
Actions at the sharp end resolve all ambiguity
Human practitioners are the adaptable element of complex systems
Human expertise in complex systems is constantly changing
Change introduces new forms of failure
Views of ‘cause’ limit the effectiveness of defenses against future events
Safety is a characteristic of systems and not of their components
People continuously create safety
Failure free operations require experience with failure

Why do computers stop and what can be done about it

Jim Gray: http://www.hpl.hp.com/techreports/tandem/TR-85.7.pdf

Dickerson's Hierarchy of Reliability

Product Development Capacity Planning Testing and Release Procedures Postmortem and Root Cause Analysis Incident Response Monitoring

https://docs.google.com/drawings/d/1kshrK2RLkW-XV8enmWZxeRFRgADj6d4Ru_w5txz_k9I/edit

Designers/Creators of Programming Languages

A quick history of software (in ascii)

hardcoded hardware (ENIAC) ->
  von neumann architecture (stored programs) ->
    mainframes with custom punch cards (assembly) ->
      procedural code (fortran, c) ->
        object oriented (simula, java) ->
          parallel programming ->
            Artificial Intelligence that writes self adapting Domain Specific Langauges for everything?

Start by reading all of the following to nitpick how the above is fast and loose with history and the truth...

Hacker's Jargon

from Hacker News https://ift.tt/Blgumeo

SymmetricalDataSecurity

Wednesday, June 1, 2022

A concise summary of software concepts