Software Development Methodologies

Understanding software development methodologies is essential for data professionals working in modern teams. The right methodology provides a systematic, efficient, and quality-oriented way of working on projects.

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What is a Development Methodology?

A methodology is a structured approach that follows a design philosophy and guides developers through each stage of development.

Well-managed projects are successful projects.

When working in a team, selecting the right methodology is critical for effective project management. Every methodology differs in its strengths, shortcomings, and the problems it was designed to solve.

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Waterfall Methodology

The waterfall method is the oldest approach to software development—a linear, sequential process.

Phases

Requirements → Design → Implementation → Verification → Maintenance

Each phase must be completed before moving to the next. There’s typically no process for going back.

Pros and Cons

Pros	Cons
Simple to understand and manage	Slow and expensive
Works well for precise, stable requirements	Rigid—hard to adapt to changes
Good for less experienced teams	Late discovery of issues
Clear documentation at each phase	Users don’t see product until late

When to Use Waterfall

• Requirements are well-defined and stable
• Regulatory environments requiring documentation
• Short projects with clear scope
• Teams with less experience

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Agile Methodology

Agile reduces risk through iterative development with small increments of new functionality.

Agile Values

1. Individuals & Interactions over processes and tools
2. Working Software over comprehensive documentation
3. Customer Collaboration over contract negotiation
4. Responding to Change over following a plan

Agile Characteristics

Aspect	Description
Time	Not constrained (iterations continue)
Budget	Not constrained
Features	The constraint—develop until sufficient
Releases	Frequent, incremental

Pros and Cons

Pros	Cons
Iterative releases improve quality	Requires experienced team
Early detection of issues	Documentation often lacking
Users see value sooner	Time and labor intensive
Adapts to changing requirements	Scope can creep without discipline

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Agile Frameworks

Scrum

The most widely-used agile framework:

Element	Description
Sprints	Short iterations (1-4 weeks)
Ceremonies	Planning, Daily Stand-up, Review, Retrospective
Roles	Product Owner, Scrum Master, Development Team
Artifacts	Product Backlog, Sprint Backlog, Increment

Key Ceremonies:

• Sprint Planning — Define sprint goals and tasks
• Daily Stand-up — 15-min sync on progress/blockers
• Sprint Review — Demo completed work
• Retrospective — Reflect and improve process

Kanban

Focuses on visualizing workflow and limiting work in progress:

Element	Description
Kanban Board	Visual representation of work
WIP Limits	Restrict work in progress
Pull System	Pull work when capacity allows
Flow	Optimize for continuous delivery

Extreme Programming (XP)

Emphasizes technical excellence:

• Pair Programming — Two developers, one keyboard
• Test-Driven Development (TDD) — Write tests first
• Continuous Integration — Integrate code frequently
• Refactoring — Continuously improve code

Lean

Minimizes waste and maximizes value:

• Value Stream Mapping — Identify waste
• Just-in-Time Delivery — Deliver when needed
• Continuous Improvement — Kaizen mindset

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Agile vs Waterfall Comparison

Aspect	Waterfall	Agile
Approach	Sequential, linear	Iterative, incremental
Requirements	Fixed upfront	Evolving
Flexibility	Low	High
Customer involvement	Beginning and end	Throughout
Documentation	Heavy	Light
Testing	End of cycle	Continuous
Risk	High (late discovery)	Lower (early feedback)
Best for	Stable requirements	Changing requirements

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Agile Software Development Lifecycle

Pre-Coding: Definition of Ready (DoR)

Before coding begins, ensure:

• User stories are clear and complete
• Acceptance criteria are defined
• Dependencies are identified
• Estimates are provided

Development Activities

1. Coding — Write the implementation
2. Code Review — Peer review for quality
3. Testing — Unit, integration, acceptance tests
4. Knowledge Sharing — Documentation, pair programming
5. Technical Debt Management — Address accumulated shortcuts

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Technical Debt

Technical debt is the implied cost of additional work caused by choosing quick solutions over better approaches.

Indicators

Category	Warning Signs
Delivery	Quality degradation, high cost of change, slow experimentation
Architecture	Hard to integrate, reuse, grow, or support
Team	Delays, low estimation confidence, demotivation

Managing Technical Debt

• Allocate time in each sprint for debt reduction
• Track debt as backlog items
• Use tools like SonarQube for code quality metrics
• Prioritize debt that blocks critical features

Code Quality Tools

SonarQube — Continuous code quality inspection:

docker run -d -p 9000:9000 sonarqube:latest

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SDLC Competency Progression

Measure your progress with the following competencies:

Foundational

• Basic understanding of SDLC phases, roles, responsibilities, artifacts
• Basic understanding of Agile and Waterfall methodologies

Intermediate

• Solid knowledge of Agile and Waterfall
• Clear understanding of roles in Agile vs Waterfall
• Ability to participate in Scrum ceremonies

Advanced

• Ability to drive Scrum ceremonies (refinement, planning, demo)
• Define and produce deliverables across methodologies
• Establish/enhance processes on a project
• Act as proxy Product Owner

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Key Takeaways

1. Waterfall = Sequential, documentation-heavy, works for stable requirements
2. Agile = Iterative, flexible, works for evolving requirements
3. Scrum is the most popular Agile framework (sprints, ceremonies, roles)
4. Kanban visualizes work and limits WIP for continuous flow
5. Technical debt must be actively managed to maintain velocity
6. Choose based on context — project type, team experience, requirement stability