A short presentation "from the guts" about what it means to write software in 2018 and why it is so much fun

1. Yves Caseau - The Joy of Programming – June 2018 1/9
// finds a cell with a min count (heuristic)
findPivot(g:Grid) : any
-> let minv := 10, cmin := unknown in
(for c in g.cells
(if (c.value = 0 & c.count < minv)
(minv := c.count, cmin := c)),
cmin)
// solves a sudoku : branch on possible
// values using a recursive function
// branch(...) does all the work :)
solve(g:Grid) : boolean
-> when c := findPivot(g) in
exists(v in (1 .. 9) |
(if c.possible[v]
branch((c.value := v,
solve(g)))
else false))
else true
// first propagation rule
r1() :: rule( c.value := v =>
(store(c.line.counts,v,0),
store(c.column.counts,v,0),
store(c.square.counts,v,0),
for v2 in (1 .. 9)
(if (v != v2 & c.possible[v2]) noLonger(c,v2),
for c2 in (c.line.cells but c) forbid(c2,v),
for c2 in (c.column.cells but c) forbid(c2,v),
for c2 in (c.square.cells but c) forbid(c2,v))))
// if c.count = 1, the only possible value is certain
r2() :: rule( c.count := y & y = 1 =>
c.value := some(y in (1 .. 9) | c.possible[y]))
// if a value v is possible only in one cell, it is certain
r3() :: rule( updateCount(cs,v) & cs.counts[v] <= 1
=> when c := some(c in cs.cells |
c.value = 0 & c.possible[v]) in
c.value := v
else contradiction!())
Yves Caseau
Michelin Group CIO
NATF (National Academy of Technologies of France)
Thinking, Designing, Writing,Thinking, Designing, Writing,
Testing … and Living with Code:Testing … and Living with Code:
Software in the 21Software in the 21stst
centurycenturyYves Caseau
Group CIO, Michelin
NATF
ADN Meetup, Le Crest
June 28th
, 2018 (v0.5)

2. Yves Caseau - The Joy of Programming – June 2018 2/9
The Need for Elegant ProgrammingThe Need for Elegant Programming
Constant change : love your code 
 Constant change & constant training
Refactoring : your code is a garden !

3. Yves Caseau - The Joy of Programming – June 2018 3/9
Software Development is a Team SportSoftware Development is a Team Sport
The world moves too fast to stay alone
 Build up your community
 Share your code to hire extra eye balls

4. Yves Caseau - The Joy of Programming – June 2018 4/9
Software is about Experience, not FunctionsSoftware is about Experience, not Functions
 User Experience Design is critical
 Cross-functional squads required
 Polyvalence makes collaboration easier

5. Yves Caseau - The Joy of Programming – June 2018 5/9
Always Ask for Help !Always Ask for Help !
In the 21st
century, to code starts with search
 Get in touch with your community for regular training
Leverage the power of MOOCs – Be curious !

6. Yves Caseau - The Joy of Programming – June 2018 6/9
Thinking and Doing in a Constant Learning LoopThinking and Doing in a Constant Learning Loop
 Analysts and Developers : 20th
century concepts 
 From mechanical design to organic growth
 Real-life operability issues makes delightful math problems

7. Yves Caseau - The Joy of Programming – June 2018 7/9
Good Software is Grown From Quantified FeedbackGood Software is Grown From Quantified Feedback
 Listen constantly to your users 
 Learn from measures – grow from your mistakes
 There is no user satisfaction without fast response time

8. Yves Caseau - The Joy of Programming – June 2018 8/9
Remember that You Belong to an EcosystemRemember that You Belong to an Ecosystem
 Your app is not isolated – recognize the system you are in
 Your users are not isolated – recognize the flows
 Don’t aim to be a “solution consultant” – be a magician !

9. Yves Caseau - The Joy of Programming – June 2018 9/9
ConclusionConclusion
Thank you for inviting me 
There has never been a better time
to write code 
Don’t build walls around yourselves 
 Let’s complete the Lean & Agile deployment

10. Yves Caseau - The Joy of Programming – June 2018 9/9
ConclusionConclusion
Thank you for inviting me 
There has never been a better time
to write code 
Don’t build walls around yourselves 
 Let’s complete the Lean & Agile deployment