Code with Honor – on the importance and beauty of software programming - RMOUG 2021 Training Days

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Code with Honor
on the importance and beauty
of software programming
Lucas Jellema – AMIS | Conclusion

RMOUG Training Days 2021 | Code with Honor 3

Quiz time

PR
PRofessionalPRide
Public Relations
Public Responsibility
PRoof Periodic Review
Pull Request
Peer Review
Production Ready
oPeRate
Put to Re
PuRpose
PR oductive
Push-button Release

We are Proud Craftsmen

The Business
17

Development
Production
scale,
performance,
security,
stability,
recoverability,
monitoring
18

0
1
2
3
4
5
6
7
3 months 2 months 1 month 0 months minus 1 month minus 2
months
Value of Software vs Production Date
Cost Value
MVP and incremental value delivery
go
live
no value!
19

Lifetime of a software application

Paid Lip Service
• Testing
• QA
• CI/CD
• Automation
• Scalability
• Production-like testing environments
• Security
• Architecture | Design Patterns

The Brake System is
powered by Software
The quality of the brake
software is similar to the
code that you (or your team)
committed last week
Your mother-in-law is
about to get into the car
Your mother-in-law is
about to get into the car
Your kids are about to
get into the car
22

why not?
what is your software good enough for?
for a demo, a PoC or a strictly controlled
prototype?
good enough to go to ACC (and let them find the
bugs)?
how do you know?
how do you know for sure what your
software does and how it deals with real
life?
23

Quiz time

What would you prefer:
 We have no failing tests
 We have some failing tests

What would you prefer:
 We have 10% failing tests
 We have 17.61 % failing tests

About me

• About you as well?
• A software professional who wants to
be proud
of the professional software
that you craft
take responsibility
towards society

source: https://www.futuristgerd.com/2016/05/my-presentation-at-innotown-2016-in-alesund-the-next-5-years-in-technology-and-innovation/

My Central Heating Guy
• Functioning system: heating and shower get water with requested
temperature (fast enough and in sufficient volume)
• Within reasonable boundary conditions (-20° to 30° outside
temperature)
• Safe & According to regulations
• Limited noise production, limited gas
• Lasts a while (10-20 years) – robust, limited wear & tear
• Not often failures, after failure system can be started again
quickly
• Can be adapted to (small) changes in circumstances
such as renovation of the house
• Maintenance: not too often and not too expensive
• CV technicians that can work with the system are widely
available, as well as spare parts: the system is not very outlandish

My Central Heating Guy
• Functioning system: heating and shower get water with
requested temperature (fast enough and in sufficient volume)
• Within reasonable boundary conditions (-20° to 30° outside
temperature)
• Limited noise production, limited gas
• Not often failures, after failure system can be started again
quickly
• Can be adapted to (small) changes in circumstances
such as renovation of the house
• CV technicians that can work with the system are widely
available, as well as spare parts: system is not very outlandish
*) We expect a professional to offer
suggestions and bring up relevant items
that I am unaware off as a layman
33

My Software Guy
• Functioning system: proof of working according to
specifications – under all foreseeable conditions
• Satisfies non-functional requirements
(performance, availability, recovery of data & service)
• Known and reasonable TCO
• with regular technical maintenance at normal costs
• Can be adapted to changes in functional and non-functional
requirements (scale, availability, performance, security, …)
• Software can be operated and maintained by regular IT staff
• no rare super specialists need to be flow in
• support and upgrades are easily available
*) We expect a professional to offer
suggestions and bring up relevant items
that I am unaware off as a layman
34

Do most systems live up to these
expectations?
Does your software?
Does mine?

Code with Honor
• Be proud
• Take responsibility
• Hone skills and craftmanship
• Focus on longevity
• Be honest
• Be productive
• Realize value
• Team up
• Step up
• No concessions to my professionalism

Productivity as function of time and code quality

Productivity as function of time and code quality
source: https://martinfowler.com/articles/is-quality-worth-cost.html
39

Working Software
• What work does it do?
• How can you tell?
Working Software

Small step for mankind…
FROM WORKING
SOFTWARE
TO PROFESSIONAL
SOFTWARE
43

Professional Software is ABLE Software
• Verifi
• Test
• Oper
• Read
• Evolv
• Maintain
• Observ
• Scal
• Recover
• Prov
• Afford
• Deploy
• Audit
• Impenetra
ABLE
44

What is software?

What is software?
Any instruction executed by a machine!

Not all code is created equal
• Demo in presentation or workshop
• Explorative / R&D / Doodles
• Assignment in study or training
• Snippet in a blog-article
• Proof of Concept
• Prototype
• MVP
• Alert Condition evaluation
• Product with a very short time to live (several weeks, not any longer)
• Contribution to open source project
• (internal) Reusable Library
• Operating system for guided nuclear missile/ SpaceX vehicle
• Unit-test for code component
• Healthcheck/smoketest
(potentially) Production : Professional Quality Software
Not Production Ready: not (necessarily) Professional Quality Software

Case in point
old
not modern
legacy
business critical
custom software
50

Case in point
end of scale
low on expertise
fragile
no tests, no specs, no docs
expensive TCO
high technical debt
no evolution
51

high incident rate
not modern
legacy
business critical
custom software
end of scale
little expertise left
on applications and tech stack
fragile
no tests, no specs, no docs
expensive: high TCO
high technical debt
no evolution
monolith
unattractive technology stack
for young talent
unsupported
inflexible
security-challenged
modern
longevity
business critical
buy before build
scalable
full command
of applications and technology
resilient
automation everywhere
pay per use, business value for money
controlled technical debt,
moving to technical solvency
continuous everything
agile architecture
appealing technology stack
for young talent and experienced staff
supported technology (N or N-1)
agile
as secure as needed
business  IT gap
productivity
robust
old
cloud
well aligned business & IT

Working Software
Working Software

Working => Professional Software
Working
Software
Professional
Software

https://www.youtube.com/watch?v=5p8wTOr8AbU

Working => Professional Software
Working
Software
Professional
Software

Stages in Software Lifecyle
Functional Specification
Behavior & Unit test
Working Software
Professional Code
Built Software
Deployable Software =
DONE
Professional &
ABLE:
Live Software
(under Ops)
Developer
Team
Production
Preparation
Team
DoR
DoaD
DoD
PRoof
Pull Request
Peer Review
Production Ready
oPeRate
Put to Rest
58

Working
• according to functional specifications and technical interfaces
• proven
Working Software
59

Behavior Test
• The required
behavior as
experienced from
the outside
• specify
• document
• verify
Functional Specification
Behavior test
Working Software
Team
DoR
60

Unit Test
• Verify behavior of
• APIs & Interfaces
• Reusable elements
• Algorithms
• Aspects
• Functionality
• Non Functionality
• Happy & Non-Happy
• not: dependencies
61

Test is many things
Functional contract (specification and documentation)
Quick (REPL) feedback cycle for developer
Proof of “working”
Insulator that allows
refactoring and code optimizations
technical upgrades
Regression detector
for things changed
and things unchanged but impacted by changes
Health indicator & Smoke detector
Reference for (re)using code
62

• Who creates the test?
• and at what time?
• Who (or what?) executes the test
• at what moment | trigger?
• what is the outcome
• Who checks on the tests?
• specification coverage
• code coverage
• [real world] condition coverage
• timely execution of test and handling of
result

Definition
• functional specifications
clear, unambiguous and understood
• boundary conditions, non happy
cases and exceptional situations are
covered in specifications
• non-functional requirements are clear
• business value of feature is defined
• TCO budget

Test Trophy
Live
65

Application Architecture
Business Logic
API/
Public
Interface
Frontend
(web, chat,
public REST)
Persistence
(of state) – pluggable
persistence providers
External
Systems
External
Systems
External
Systems

Application Architecture
Business Logic
API/
Public
Interface
Frontend
(web, chat,
public REST)
Persistence
(of state) – pluggable
persistence providers
External
Systems
mock
mock
mock
External
Systems
External
Systems

QA: Static Code Analysis
• According to coding standards
• Consistent
• Readable (naming, formatting, length, …)
• Maintainable (Code Smells)
• Limited complexity
• Code Coverage (of tests)
• Vulnerabilities (in dependencies)
• Automatic improvements

Refactoring
73

Refactoring towards Clean Professional Code
• Compliance with
coding standards
• Reducing complexity
• Increasing readability
• Testable & test coverage
• Operable
• logging
• metrics
• configuration settings
• Life cycle management of technology stack &
technical debt
• Needed: Local build pipeline and runtime environment to quickly and frequently do
code analysis, pull & merge from master, build & automated test
Working Software
Professional Code Developer
DoaD
Unit tests & QA
(Behavior Tests)
Refactoring
74

private void calculatePayroll (SpecialList<Employee> employeeGroup) {
while (employeeGroup.HasMore()) {
Employee employee = employeeGroup.getNext(true) ;
employee.updateSalary() ;
Payroll.distributeCheck(employee) ;
}
}
private void process (SpecialList
g) { while (g.
HasMore()) { e =
g.getNext(true) ; e.
updSal
() ; /* discard check for temp workers */ Prl.
disChk(e) ; }
}
75

Clean
Code
Guidelines
76

Team
• That story is in Janet’s area
• Sorry, Tom is on leave so we cannot work on X
right now
• Our tester is working on running all automated
tests
• Ellen is the only one on our team who can work on
the Python components
• Thomas knows how the CI/CD pipelines work
• I am not sure what business feature Sophie is
working on this sprint
• Bob built it, he knows how to demo it
• This [one year] old code is hard to maintain
because the person who built it has left the team

Metamorphosis – the miracle of the PR
79

PR
Pull Request
Peer Review
Production
Ready
Metamorphosis – the miracle of the PR

Pull Request == Please Review ?!
Team
DoaD
Appreciate my work
and learn from it
Help me improve it
and become a better developer
Take co-ownership of this code
81

Peer Review completes the Pull Request
• Peer Review completes (only) when
• Code is ABLE
• and beautiful
• the code is merged from the branch to the trunk
• and the tram may roll in
• because the peer considers the code their own
• Give priority to Peer Review!
• respond ASAP to Pull Request
• a proper Peer Review takes
real commitment and substantial time
(proportional to the complexity of the story)
Team
82

Definition of Almost Done
• Code on trunk
• ABLE
• Compiles | Can be Built
• Satisfies
• QA
• Test (behavior & code)
• Non-functional characteristics (absolute & trend)
• Vulnerability
• Guidelines and Standards
• Automated CI/CD pipeline
• (covered by) Smoketest
• Technical Debt management
Professional Code
Built Software
83

Deployable == Done (as far as team is concerned)
• Deployable – but not yet deployed
• deploy decision is up to business
• CI/Continuous Delivery =
fully process up to deployability
• Continuous Deployment: automatic roll
out when DONE
Professional Code
Built Software
DONE
DoD
84

Deploy
• Business decision
• Automated – no touch
• Smoketest post deployment
(and periodically to check on health)
• Operations activated
Built Software
DONE
Professional &
ABLE:
Live Software
(under Ops)
Production
Preparation
85

Canary
87

Observe the canary

Professional Software – Generating Value for the Business

Software Wears Down

Life Cycle Management – Technical Maintenance
• Ensure the up-date-ness of
the application and all its dependencies
Periodic Review
93

Life Cycle Management – Technical Maintenance
• A CEV vulnerability (CVE database https://www.cvedetails.com/)
• Release (or patch) of 3rd party library/framework
• New or deprecated (feature in) PaaS Service
• Custom pricing in used or unused service
• New specification from the business
• New non-functional requirement
• Incident/bug – functional or non-functional
• Technical debt assessment
• New version of platform component:
• e.g. Docker, Kubernetes, Java, Node
• New/custom architecture
choice/guideline
• New/custom coding standard
• New tool, new version of tool
• Law & Regulation, Ethical Insights
• Mere Progression of Time
Triggers for technical change – proactively monitored by the DevOps Team
Periodic Review
94

What Time can Do…

PR
PRofessional
PRide
Public Relations
Public Responsibility
PRoof Periodic Review
Pull Request
Peer Review
Production Ready
oPeRate
Put to Re
PuRpose
PR oductive
Push-button Release

Thank you
for your attention
I hope
this was
useful
lucas.jellema@amis.nl | technology.amis.nl | @lucasjellema | lucas-jellema
97

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