The Software Development Life Cycle (SDLC) is a defined set of steps that software engineering teams follow to develop and maintain software applications. The SDLC defines the predictable stages involved in developing any piece of software as well as the standards for transitioning from one stage to another. All software engineering teams use some form of SDLC. Using an SDLC makes the development process measurable and therefore improvable.
The SDLC typically covers six core phases:
Order, overlaps, and phase repetitions can vary across software development methodologies. It is the differences in these aspects that distinguish each SDLC methodology from another.
The wrong choice of an SDLC model can hinder a software development process even before its completion. For instance, when the wrong approach is used to develop software that changes quickly, much time may be spent revising the requirements documentation rather than adding new features to the application. In contrast, if there are no structured cycles when creating a critical system, the result can be defective software.
The right SDLC methodology depends on four factors:
This decision matters especially when working with distributed or augmented teams. When a company scales engineering through a partner like Talmatic – connecting EU tech companies with vetted remote developers – aligning on a shared SDLC methodology from day one prevents costly miscommunication and ensures every contributor operates within the same development process.
The waterfall model is the oldest methodology for software development. This process involves passing through distinct stages in sequence, including requirement gathering, design, implementation, testing, and deployment. One has to complete one stage before moving on to the other. The software requirements are established at the initial stage of development. If any modification is required later, one has to revert to the previous stages, which is costly.
Waterfall is an approach to project management that provides clearly defined phases and documentation, thereby facilitating long-term planning. Nonetheless, this approach is not very useful in projects whose requirements keep changing. The major disadvantage of the waterfall model arises when there is a need to alter the project’s requirements.
Despite all its disadvantages, Waterfall remains popular for managing government projects and projects involving embedded systems.
The V-Model extends the Waterfall by pairing every development phase with a corresponding testing phase. For every design decision, there is a planned verification step – represented visually by the model’s V shape. This model is the best for safety-critical systems – aerospace, medical devices, and financial infrastructure.
Agile Model is the result of the 2001 Agile Manifesto, which is the response to some constraints associated with the Waterfall Model. The basic principles of this methodology emphasize the importance of delivering functional software earlier and more often, responding to change rather than following a preconceived plan, and continuously collaborating with the customer rather than treating it as a one-off effort.
Scrum is the most widely adopted Agile framework. Work is organised into fixed-length iterations called sprints – typically 1–4 weeks – and each sprint produces a potentially shippable product increment.
Key roles in a Scrum team:
The visual approach in Kanban is achieved through cards that represent tasks. WIP constraints are applied in order to avoid delays. As opposed to Scrum, which employs fixed-length iterations, Kanban allows for the continuous flow of work starting from the initial backlog up to completion. This process is appropriate for operational pipeline processes, support units, and delivery activities.
Extreme Programming (XP) improves Agile practices by emphasizing techniques such as pair programming, test-driven development (TDD), continuous integration, and constant releases. It’s best for small teams where technical debt and defect rates are critical metrics.
There are many features that make up DevOps, and the most important aspect is that it combines development and operations through automation. With CI/CD pipelines, companies can ship multiple releases per day. This is because software testing is performed as part of the pipeline, rather than at the end of the process. DevOps is very common in software-as-a-service (SaaS), e-commerce, and cloud applications.
SAFe or the Scaled Agile Framework, assists businesses in implementing Agile methodology through collaboration between several teams involved in developing software. SAFe relies on Program Increment (PI) and ARTs or Agile Release Trains to help teams collaborate effectively without losing flexibility during sprints. The use of SAFe is effective in dealing with complex business environments and processes. Organizations tend to implement SAFe in cases where many developers participate in the development process in several teams.
The Spiral model combines the structured phases of the Waterfall model with iterations. These four phases consist of planning, risk assessment, construction, and evaluation. The advantage of the Spiral model is that risk assessment becomes a key component of the development process. The Spiral model is typically chosen when there is a need for risk management and evaluation.
No single SDLC methodology is universally optimal. The table below maps the most common approaches against the variables that most influence the right choice.
| Methodology | Best for | Flexibility | Documentation | Risk Tolerance |
| Waterfall | Fixed-scope projects | Low | High | Low |
| V-Model | Safety-critical systems | Low | Very High | Very Low |
| Scrum | Iterative product development | High | Moderate | High |
| Kanban | Continuous delivery | High | Low | High |
| DevOps | Frequent releases | Very High | Low | High |
| SAFe | Enterprise at scale | Moderate | High | Moderate |
| Spiral | High-risk, long projects | Moderate | High | Low |
Most mature engineering teams run a hybrid. Scrum sprints within a DevOps pipeline are the most common pattern. SAFe at the program level with Kanban at the team level is another established approach. The goal is not methodological purity – it is predictable, quality delivery.
Choosing a software development lifecycle methodology is one of the earliest and most consequential decisions on any software project. Match the method to your constraints – not to trend or tradition – and revisit it as your team and product evolve. The frameworks above are not competing schools of thought: they are tools, each built to solve a specific set of problems.
The Software Development Life Cycle involves many approaches, such as Waterfall, V-Model, Scrum, Kanban, Extreme Programming (XP), DevOps, SAFe, and the Spiral Model. Each approach can be applied to projects of different scales and at different intervals.
Scrum is the best Software Development Life Cycle (SDLC) framework that works well for start-ups. This is because sprints ensure responsibility, whereas the backlog can be used when priorities change . Another feature about Scrum is that it scales as more members join.
The waterfall model defines software requirements systematically before development begins. On the other hand, the agile model views requirements as dynamic and focuses on the delivery of value through small increments and constant interaction with the client. The waterfall approach suits projects with a predefined scope, whereas the agile model suits user or market-defined projects.
Teams assess four factors: requirement volatility, regulatory constraints, team size and distribution, and the client’s expectations around delivery cadence. A startup building a consumer app and a bank building payment infrastructure will reach different answers to the same question – and both will be correct for their context.