How I finally stopped worrying and learnt to love Conways Law - - PowerPoint PPT Presentation

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How I finally stopped worrying and learnt to love Conways Law - - PowerPoint PPT Presentation

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How I finally stopped worrying and learnt to love Conways Law James Lewis 1 ORGANIZATIONS WHICH DESIGN SYSTEMS ARE CONSTRAINED TO PRODUCE DESIGNS WHICH ARE COPIES OF THE COMMUNICATION STRUCTURE OF THOSE ORGANIZATIONS Melvyn

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How I finally stopped worrying and learnt to love Conway’s Law

James Lewis

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“…ORGANIZATIONS WHICH DESIGN SYSTEMS … ARE CONSTRAINED TO PRODUCE DESIGNS WHICH ARE COPIES OF THE COMMUNICATION STRUCTURE OF THOSE ORGANIZATIONS”

Melvyn Conway, 1968

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The mirroring phenomenon is consistent with two rival causal

  • mechanisms. First, designs may evolve to reflect their development
  • environments. In tightly-coupled organizations, dedicated teams

employed by a single firm and located at a single site develop the

  • design. Problems are solved by face-to-face interaction, and

performance “tweaked” by taking advantage of the access that module developers have to information and solutions developed in

  • ther modules. Even if not an explicit managerial choice, the

design naturally becomes more tightly-coupled. By contrast, in loosely-coupled organizations, a large, distributed team of volunteers develops the design. Face-to-face communications are rare given most developers never meet. Hence fewer connections between modules are established. The architecture that evolves is more modular as a result of the limitations on communication between developers.

4 http://www.hbs.edu/faculty/Publication%20Files/08-039_1861e507-1dc1-4602-85b8-90d71559d85b.pdf

"Exploring the Duality between Product and Organizational Architectures : A Test of the “Mirroring” Hypothesis"

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microservices should be:

cheap to replace and should allow you to go as “fast as possible”? quick to scale withstand failure

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Difficulties I hear about a lot:

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Difficulties I hear about a lot:

End-to-end testing

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Difficulties I hear about a lot:

End-to-end testing Independent deployment

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Difficulties I hear about a lot:

End-to-end testing Independent deployment Service versioning / evolution

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THE THING I MOST WORRY ABOUT IS NOT TESTING, DEPLOYMENT OR VERSIONING

IT’S ORGANISATIONAL DESIGN

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A TYPICAL COMPANY

I got approximately 5 problems out of a maximum of about 20- I reckon

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develop- ment

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testing architects

  • ps

PMO HR sales marketing finance

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develop- ment

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testing architects

  • ps

PMO HR sales marketing finance

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SLIDE 16 13 Project(process( 1( Business IT Solutions dev QA Support Idea High level Estimation and decision to proceed Deploymen t Testing Business Requirement Document Business Case Project Brief Functional spec Initiation Doc reqs. matrix Detailed Estimate Project Approve d TDD PM docs Test Script s Change Request Requirement s clarification and estimation 1010100010100101011010 Dev Kick off Coding (Dev) Additional <thing> raised >10 % CAPE X <10 % CAPE X Support handover User Acceptance Testing Normal Flow Data Flow Alternate Process Flow KEY Dropped requirements become Enhancements
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develop- ment

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testing architects

  • ps

PMO HR sales marketing finance

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each of these chords represents a delay

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“There is nothing so useless as doing efficiently that which should not be done at all”

Peter Drucker

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CASE STUDY

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Fulfilment Retail

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Fulfilment Retail

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Fulfilment Retail

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Fulfilment Retail

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Fulfilment Retail

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A capability is a combination of people, processes, systems that provides value to customers (internal or external)

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Fulfilment Retail

EACH CAPABILITY WAS BUILT BY A LARGE TEAM

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Fulfilment Retail

WHICH WERE FORMED INTO SHORT-LIVED PROJECT TEAMS

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Fulfilment Retail

WHICH WERE FORMED INTO SHORT-LIVED PROJECT TEAMS

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Fulfilment Retail

WHICH WERE FORMED INTO SHORT-LIVED PROJECT TEAMS

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Fulfilment Retail

WHICH WERE FORMED INTO SHORT-LIVED PROJECT TEAMS

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Fulfilment Retail

WHICH WERE FORMED INTO SHORT-LIVED PROJECT TEAMS

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AND THE SYSTEMS ENDED UP LOOKING LIKE THIS:

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Feature starts dev

iteration 2 iteration 1 iteration 3

Feature deployed

regression testing performance testing deployment tests

cycle time

BUILT USING SCRUMERFALL

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SLIDE 39 32 Unit Tests Build Service Tests

Service A

Build

Service B

End-to-end Tests Build

Service C

Build

Service D

Service Tests Unit Tests Unit Tests Unit Tests Service Tests Service Tests

NEEDED TO BE TESTED TOGETHER

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AND DEPLOYED TOGETHER

write spec write code test release

Without deploying into production, inventory is built up - inventory costs money and the more we have the more risky our deployments

?

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beware the distributed monolith!

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this is a recipe for a nervous breakdown

this is not “as fast as possible”

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WHAT MIGHT GOOD LOOK LIKE?

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Pauline Cafferkey

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Team at the Royal Free

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infectious diseases

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lab services facilities domestic services physio micro biology estates pharmacy finance

Royal Free Hospital Capabilities

<other> <other>

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infectious diseases

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lab services facilities domestic services physio micro biology estates pharmacy finance

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“The approach favors agility over raw power <snip>”

http://en.wikipedia.org/wiki/OODA_loop
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SLIDE 50 43 1 Dr Rebecca Lester, Infectious diseases, Specialist registrar 2 Dr Damien Mack, Microbiology, Consultant 3 Dr Ruaridh Buchanan, Infectious diseases, Specialist registrar 4 Dr Simon Warren, Infectious diseases, Consultant 5 Oliver Carpenter, Infectious diseases, Nurse clinical practice educator 6 Breda Athanasopoulos, Infectious diseases, Senior matron lead high level isolation unit 7 Dr Tabitha Mahungu, Infectious diseases, Specialist registrar 8 Susan Coath, Infectious diseases, Ward sister 9 Zenaida Pandio, Domestic services, Housekeeper 10 Claire Harawa, Domestic services, Domestic team leader 11 Renato Pandio, Domestic services, Deep cleaner 12 Sheila Connolly, Patient environment, Head of patient environment 13 Peter Williams, Facilities, Security manager 14 Marchito Tumibay, Domestic services, Support worker 15 Michael Campo, Facilities, Porter 16 Lauren Geddes, Physiotherapy, Clinical lead cardiorespiratory care 17 Victoria Maddox, Laboratory service, Senior health care scientist 18 Nikki Williams, Infectious diseases, Ward sister 19 Dr Sanjay Bhagani, Infectious diseases, Consultant 20 Sarah Stanley, Patient at risk team, Nurse consultant 21 Dr Susan Hopkins, Infectious diseases and microbiology, Consultant 22 Torrain Exall, Physiotherapy, Clinical lead critical care 23 Dr Stephen Mepham, Infectious diseases and microbiology, Consultant 24 Dr Michael Jacobs, Infectious diseases, Consultant 25 Simon Rattenbury, Laboratory service, Head of laboratory service 26 Bryan O’Farrell, Pharmacy, Senior Pharmacist 27 Adrien Cooper, Estates, Director of estates 28 Robert Elliot-Cooke, Pharmacy, Senior pharmacist 29 Allan Harris, Estates, Engineering supervisor 30 Sumal Kuranaratne, Facilities, Support services manager 31 Dave Reavy, Facilities, Head of security and support services 32 Garba Ibrahim, Domestic services, Domestic team leader 33 Stephen King, Royal Free Charity, Head of finance
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SLIDE 51 44 1 Dr Rebecca Lester, Infectious diseases, Specialist registrar 2 Dr Damien Mack, Microbiology, Consultant 3 Dr Ruaridh Buchanan, Infectious diseases, Specialist registrar 4 Dr Simon Warren, Infectious diseases, Consultant 5 Oliver Carpenter, Infectious diseases, Nurse clinical practice educator 6 Breda Athanasopoulos, Infectious diseases, Senior matron lead high level isolation unit 7 Dr Tabitha Mahungu, Infectious diseases, Specialist registrar 8 Susan Coath, Infectious diseases, Ward sister 9 Zenaida Pandio, Domestic services, Housekeeper 10 Claire Harawa, Domestic services, Domestic team leader 11 Renato Pandio, Domestic services, Deep cleaner 12 Sheila Connolly, Patient environment, Head of patient environment 13 Peter Williams, Facilities, Security manager 14 Marchito Tumibay, Domestic services, Support worker 15 Michael Campo, Facilities, Porter 16 Lauren Geddes, Physiotherapy, Clinical lead cardiorespiratory care 17 Victoria Maddox, Laboratory service, Senior health care scientist 18 Nikki Williams, Infectious diseases, Ward sister 19 Dr Sanjay Bhagani, Infectious diseases, Consultant 20 Sarah Stanley, Patient at risk team, Nurse consultant 21 Dr Susan Hopkins, Infectious diseases and microbiology, Consultant 22 Torrain Exall, Physiotherapy, Clinical lead critical care 23 Dr Stephen Mepham, Infectious diseases and microbiology, Consultant 24 Dr Michael Jacobs, Infectious diseases, Consultant 25 Simon Rattenbury, Laboratory service, Head of laboratory service 26 Bryan O’Farrell, Pharmacy, Senior Pharmacist 27 Adrien Cooper, Estates, Director of estates 28 Robert Elliot-Cooke, Pharmacy, Senior pharmacist 29 Allan Harris, Estates, Engineering supervisor 30 Sumal Kuranaratne, Facilities, Support services manager 31 Dave Reavy, Facilities, Head of security and support services 32 Garba Ibrahim, Domestic services, Domestic team leader 33 Stephen King, Royal Free Charity, Head of finance
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SLIDE 52 45 1 Dr Rebecca Lester, Infectious diseases, Specialist registrar 2 Dr Damien Mack, Microbiology, Consultant 3 Dr Ruaridh Buchanan, Infectious diseases, Specialist registrar 4 Dr Simon Warren, Infectious diseases, Consultant 5 Oliver Carpenter, Infectious diseases, Nurse clinical practice educator 6 Breda Athanasopoulos, Infectious diseases, Senior matron lead high level isolation unit 7 Dr Tabitha Mahungu, Infectious diseases, Specialist registrar 8 Susan Coath, Infectious diseases, Ward sister 9 Zenaida Pandio, Domestic services, Housekeeper 10 Claire Harawa, Domestic services, Domestic team leader 11 Renato Pandio, Domestic services, Deep cleaner 12 Sheila Connolly, Patient environment, Head of patient environment 13 Peter Williams, Facilities, Security manager 14 Marchito Tumibay, Domestic services, Support worker 15 Michael Campo, Facilities, Porter 16 Lauren Geddes, Physiotherapy, Clinical lead cardiorespiratory care 17 Victoria Maddox, Laboratory service, Senior health care scientist 18 Nikki Williams, Infectious diseases, Ward sister 19 Dr Sanjay Bhagani, Infectious diseases, Consultant 20 Sarah Stanley, Patient at risk team, Nurse consultant 21 Dr Susan Hopkins, Infectious diseases and microbiology, Consultant 22 Torrain Exall, Physiotherapy, Clinical lead critical care 23 Dr Stephen Mepham, Infectious diseases and microbiology, Consultant 24 Dr Michael Jacobs, Infectious diseases, Consultant 25 Simon Rattenbury, Laboratory service, Head of laboratory service 26 Bryan O’Farrell, Pharmacy, Senior Pharmacist 27 Adrien Cooper, Estates, Director of estates 28 Robert Elliot-Cooke, Pharmacy, Senior pharmacist 29 Allan Harris, Estates, Engineering supervisor 30 Sumal Kuranaratne, Facilities, Support services manager 31 Dave Reavy, Facilities, Head of security and support services 32 Garba Ibrahim, Domestic services, Domestic team leader 33 Stephen King, Royal Free Charity, Head of finance
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“If you imagine all the functions a hospital has to have, not only the doctors and nurses and physiotherapists and pharmacists but estates management and food and facilities and laundry — they all have to be involved, and they all have to be specially trained to be safe to work in that environment. “

Dr Michael Jacobs - Consultant, infectious disease

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infectious diseases

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lab services facilities domestic services physio micro biology estates pharmacy finance

Royal Free Hospital Capabilities

<other> <other>

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infectious diseases

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Ebola treatment

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single purpose

cross-functional teams

focussed entirely on ‘customer’ outcome

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In our study at a large Australian Telco, we found that stories leaving a team cycled 12 times slower than those that stayed in the team.

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This is true for Trauma teams in hospitals And Formula 1 teams And “reinforced battle groups”

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A SOFTWARE EXISTENCE PROOF…

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develop- ment

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testing architects

  • ps

PMO HR sales marketing finance

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x-func teams organised around lines of business

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HR sales marketing finance

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insurance company

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insurance company

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separate lines of business

home motor life

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separate lines of business

and cross-cutting capabilities home motor life my account

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cross-functional teams delivering lines of business

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x-func teams organised around lines of business

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HR sales marketing finance

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x-func teams organised around lines of business

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HR sales marketing finance

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x-func teams organised around lines of business

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HR sales marketing finance

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DEVOPS!!!

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DEVOPS!!!

Well, continuous delivery…

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x-func teams organised around lines of business

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  • ps

HR sales marketing finance

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  • ps

HR sales marketing finance Continuous Delivery

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  • ps

HR sales marketing finance

Continuous Delivery

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Continuous Delivery

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HR sales marketing finance

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Continuous Delivery

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HR sales marketing finance

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each of these capabilities can be tested and deployed independently

and cross-cutting capabilities home motor life my account

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CAN WE GO FURTHER?

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Lines of business

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Lines of business

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Value streams

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Value streams

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teams

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teams

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each team

  • wns one or more services
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~10-20

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~160-200 ~10-20

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~160-200 ~10-20

multiples thereof

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Thomas J. Allen, 1977

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10 20 30 40 50 60 70 80 90 100 0.05 0.10 0.15 0.20 0.25 0.30 m Probability of weekly interaction

x x x x x xxxxxxxx x x x x x x x x

The effect of distance on communication

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co-locate as much as possible

take advantage of serendipitous conversations

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HOW DOES THIS HELP WITH TESTING AND DEPLOYMENT?

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The microservice stability onion

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Low change rate

inter-line of business

High stability Semantic Versioning Contract Testing Tolerant Reader “Conversational change”

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higher change rate

inter-value stream

lower stability Semantic Versioning Contract Testing Tolerant Reader “Conversational change”

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higher change rate

inter-team

lower stability Semantic Versioning Contract Testing Tolerant Reader “Conversational change”

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highest change rate

intra-team

lowest stability Semantic Versioning Contract Testing Tolerant Reader “Conversational change”

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https://www.flickr.com/photos/snippets101/2686592689/ https://creativecommons.org/licenses/by-nd/2.0/

Thoughts to finish

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The Inverse Conway Manoeuvre

Design the organisation you want, the architecture will follow (kicking and screaming).

Evan Bottcher, ThoughtWorks

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WATCH OUT FOR SIGNALS:

constantly ordering work across capabilities splitting stories between teams moving people around deploying in lock-step fan-in for end-to-end testing

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IT BECOMES MUCH EASIER TO TEST AND DEPLOY INDEPENDENTLY WITH CONWAY’S LAW HELPING

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THE THING I MOST WORRY ABOUT IS NOT TESTING, DEPLOYMENT OR VERSIONING

IT’S ORGANISATIONAL DESIGN

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and that’s why I finally learned to stop worrying and love Conway’s Law

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Questions?

Please remember to evaluate via the GOTO Guide App

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FSM: Sarah Pierce. albinobloodsugar.deviantart.com ebola virus: CDC/Cynthia Goldsmith - Public Health Image Library, #10816 Jez Humble face - Release! the game - https://inedo.com/release