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- [Presenter] DevOps, including
the underlying technical,

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architectural and cultural practices,

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basically converge many
technical and project management

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and also management movements in nowadays.

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So before we start defining
what is actually DevOps,

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let's actually take a look at the history

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of the development methodologies.

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So in the past we actually had things

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like the waterfall method

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and basically that model is a software

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and hardware development and
project management methodology

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that at least has five to seven phases.

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And basically they all
follow a strict linear order.

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So one phase cannot start

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until the previous phase
has been completed.

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There are a few reasons

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why organizations use the
waterfall methodology.

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One of the main reasons is because

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the project requirements are
agreed upon from the beginning.

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So subsequently,

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planning and scheduling is actually

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a little bit simpler and
a little bit more clear.

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And a fully laid out project schedule

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and accurate estimates.

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Basically, you can potentially

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think about project costs

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and resources and deadlines
from the beginning.

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However, the disadvantage
of this methodology

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is that it can be difficult for customers

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to enumerate and communicate
all of their needs

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at the beginning of the project.

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So if your end customer
is actually dissatisfied

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with the product in the
verification phases,

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it can actually be very costly

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to actually go back all the way back

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and design the code again.

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And then of course
provide some type of fix

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for whatever the case that
your customer actually brings.

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So in the waterfall methodology,

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that linear project plan is actually rigid

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and lacks a lot of flexibility

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for adapting unexpected events.

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Then you have the Agile methodology

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and Agile is a software development

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and project management process

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where a project is actually managed

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by breaking it up into several stages

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and then involving constant collaboration

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with all stakeholders and
also continuous improvement

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and interaction or iteration
at every single stage.

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Now, the Agile methodology begins

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with end customers basically describing

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how the final product will
be used in their environment

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and clearly articulating

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what problems they actually
are trying to solve.

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And then once the coding begins,

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all the respective teams
cycles through a process

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of planning and executing and evaluating

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all these developing phases and stages.

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Now, this process may allow

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for the final deliverable to change

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in order to better fit the customer needs.

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So that's why a lot of people

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historically, and nowadays

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still actually use the Agile methodology

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to have more flexibility
in their environment

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and throughout the developing process.

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In Agile, the input to
the developing process

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is actually the creation
of a business objective.

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A concept, an idea, or
some type of hypothesis

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that you may actually have for the work.

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Then the work is added
to a committed backlog.

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And then from there, the
software development teams

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actually will follow that standard, Agile,

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or iterative process to transform

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that idea into user stories.

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And this is actually a
terminology from Agile.

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And then those user stories
will actually have some type

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of feature specification.

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Now, this specification is
then implemented in code.

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Then the code of course is also checked

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into a version control repository.

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Things like GitHub or GitLab
and many others are there.

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Now, there's also a concept adopted

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by many organizations related to Agile.

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And that concept is called Scrum.

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Scrum is basically a framework
that helps organizations

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to actually work together

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because it encourages teams
to learn through experiences.

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And basically there's a concept

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of self-organization while
working on a solution

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and then reflecting on
their wins and losses

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to continue to improve.

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Now, Scrum is actually used
by software development teams.

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However, it is also a principle

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and lesson that can be applied

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to all kinds of teamwork as well.

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Now, Scrum describes a
set of meetings, tools,

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roles that basically will work

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in concert to help teams
structure and manage their work.

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Scrum.org has a set of resources

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even a certification
and training materials

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that are related to Scrum.

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For the purpose of this exam,

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you only have to actually know

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the different Agile
methodologies and what Scrum is,

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and Scrum Master, which
is actually the person,

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typically a project manager

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that is orchestrating all the developing,

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I guess the project deliverables

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and all the different milestones

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and the tasks and so on.

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Now, talking about tasks,

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the Scrum framework uses
the concept of sprints

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and those are a short timeboxed period

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whenever the Scrum team actually works

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to complete a predefined amount of work.

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Now, sprints are one of the key concepts

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of the Scrum and Agile methodologies.

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Now, there are three
general ways to DevOps.

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The first way or method
includes systems and flow.

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And this way or method, you
actually make work visible

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by reducing the work batch sizes.

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Basically you also reduce
the intervals of work

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and prevent defects from being introduced

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by building in quality and
control throughout the process.

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The second way includes a feedback loop

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to prevent problems from happening again.

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Basically enabling you
to do faster detection

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and recovery by seeing
problems as they occur,

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and maximizing opportunities
to learn and improve

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throughout your process.

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In a true DevOps environment,

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you actually conduct dynamic
and disciplined experimentation

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and you also are allowed
to take risks as well.

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So you define the time to fix issues

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and make systems better.

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The creation of shared code
repositories help tremendously,

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things like GitHub and GitLab.

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It definitely helps you significantly

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to achieve this continuous experimentation

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and learning process.

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Now, the last concept

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that I want to introduce here
is continuous integration

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or CI, which is a software
developing practice

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were programmers merge
code in an ongoing basis.

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Basically in a central
repository like GitHub

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or GitLab and many others,
multiple times a day.

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And then you also have
continuous delivery or CD,

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that sits on top of CI.

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And basically in many cases,

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you refer to this as your CI/CD pipelines.

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And this provides a way

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for automating the entire
software release process.

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So whenever you adopt
the CI/CD methodologies,

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each change in code will actually trigger

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an automated build and test sequence.

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This automation actually
also provides feedback

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to the programmers who
actually made the change

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from the start.

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CI/CD has been adopted
by many organizations

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that provide cloud services,

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including software as a service,

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platform as a service, and so on.

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For example, the continuous delivery

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can actually include cloud
infrastructure provisioning

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and deployment, which basically,

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in the past, you have
done all this manually.

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And then it also consisted
in multiple stages.

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And now with the CI/CD process,

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this can be fully automated

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with each run fully logged and
visible to the entire team.

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That's a huge, huge benefit
of today's modern world.