ARCHITECTURE EVOLUTION FROMAMORPHOUSMONOLITHAPPLICATIONTOAMODULAR,CLOUDREADYPLATFORMCoraliaPopa–April2020

Agenda

•  Themonolith•  Layeredarchitecture• ApplicaFonssegregaFon•  Servicebasedmodulararchitecture•  Switchtodualdeployment:onpremiseandcloud•  Finalthoughts

The monolith in numbers

•  5yearsago•  15yearsoldapplicaFonatthatFme•  2yearsreleasecycle•  100+noncollocatedengineers•  3sourcesofcomplexity:integraFonwithanalyFcalinstruments,regulatorycompliance,specificdataprocessingalgorithms

•  2typesofdeployment:workstaFon,network•  3Ferarchitecture:database,businesslogicandpresentaFon•  3pathsleadingtomonolith:codemanagement,deployment,runFme•  50+verFcalslicecomponents

The monolith as a diagram

The monolith as in a list of problems

EXTREMELYLOWSPEEDOFFEATUREDELIVERY

BIGRISKOFREGRESSIONDURING

MAINTENANCE

REDUCEDOPPORTUNITYTOCHANGE

TECHNOLOGIES

PERFORMANCENEVERALLOWEDSCALINGTO

THENEEDEDPARAMETERS

INDUSTRYTRENDSINCOMPATIBILITY

The turning point

Decision point

Incrementalevolu@onthroughrefactoringorBigBangrewrite?

•  ImprovedcomponenFzaFonthroughrefactoring•  Breakthe“code”monolithbylayeredarchitectureforbusinesslogic

•  Gradualreplacementwithrewrite

Layered architecture

Layered architecture - Believes and hopes • bo]omlayerscanbestabilized• be]erunderstandingofchangeimpact• simplercontrolofdependencies• be]ertestabilityofthebusinesslogic• enablethepresentaFontoevolveatdifferentchangepace

• Coreso^wareprinciplespower•  Reuse-releaseEquivalence•  Common-Reuse•  Stable-Dependencies•  AcyclicDependencies

First signs of recovery

•  Couldreleasetwicewiththesameversionofthebo]omlayers•  Therateofchangesonthebo]omlayersondescendenttrend•  DevelopmentofnewapplicaFoncouldbestartedontopofthenewlayers

•  But…•  DemoralizedengineerteamsgiventhemassiveeffortwithnotmuchsaFsfacFon•  Hardtodemonstratetothemanagementtheoutcomeofinvestment

Next step in evoluHon - Break down the “runHme monolith”

Decision point

DRYversusLOOSECOUPLINGdilemma•  DramaFcandunpopulardecisiontocopyalargeamountofcodejusttostepintherightdirecFon

Benefits •  AlmostimpossibletoaddcouplingbetweenapplicaFonapps

•  DistribuFonoftheloadindifferentprocesseshelpedinsomeextendwithperformance

•  Releasecadencereducedtoaquarteralready,theoriginalobjecFvewasreached

But•  Startedtohaveissueskeepingtheinstancesofthelayersinsyncbetweenapps

Next step in evoluHon - Break the deployment monolith

Autonomous service paNern

•  coversadomainfuncFonality•  loosely-coupledcomponentsfollowinghexagonalarchitecture

•  easyadopFonasispopulararchitecture•  widesetoftesFngopFons•  nostate•  clearrulesforgovernance•  runninginitsownprocess

Decision point

•  CustomCodeorThirdpartyso^ware?Shouldwewelcomethirdpartyso^ware?

•  Thirdpartydependenciescanbecontrolledaswell

•  Standardsareimportant•  Thecorebusinessdomainiswhatwearegoodat

•  Everythingelseissomeoneelse’sexperFsearea

•  Thereisalibraryoratoolforeverything•  Speedupdevelopment

Decision point

• ArewereadytobeaSaaScompany?Shouldwetakea“cloudfirst”approachfornewdevelopment?

•  itwasatoughbusinessdecisionmadewithconfidencethattheso^wareteamwillbeabletodeliver• paradigmshi^oftheorganizaFon,asitappliestoalargerscopethanjustthisproductdevelopment

Next step in evoluHon – Cloud & On premise

-  “dual”applicaFons-  2PlaformimplementaFons:Cloudand“Onpremise”

Current challenges •  Security•  ComplexityoftoolslikeKubernetes

•  Growskillsinsidedevelopmentteams•  Regulatorycomplianceseemsatopicinearlyagesincloud

•  ConnecFvitywiththeanalyFcalinstrumentsinthelab

Thisisthepathfortoday,andnewlearningwillcome…

Summary

2016• Rearchitecturedecision

2017•  LayerscreaFon

2018• ApplicaFonsegregaFon

• Rewritestart

2019•  Plaform&applicaFons

• Quarterlyrelease

2020• Cloud•  Scalability

Personal retrospecHve

Theexperiencereallyhelpedmetogrowasso^warearchitect.

Decisionscouldsaveoraddmonthsofworkondevelopment

teams.

SaFsfacFonishugewhenyouseethatwhatyoudesignedisactually

working.

QuesHons?