The Software Development Life Cycle Explained
Doris Infotech
The software development life cycle (SDLC) is how teams turn an idea into running software without pretending that coding is the only work. Requirements, design, implementation, testing, deployment, and maintenance are stages with different questions. If you skip one, you still pay for it - in production, in rework, or in a product nobody wanted.
At Doris Infotech we use SDLC as a shared language with clients, not as a rigid waterfall. Agile, sprints, and continuous delivery still follow the same stages. They just run them in smaller loops so you learn before the budget is gone.
Explaining SDLC is explaining who decides what, when software is “done enough” to ship, and who owns it after launch.
Plan and requirements: name the problem
Who is this for, what job must it do, what is out of scope, and how will we know it worked? Write acceptance in user language. A backlog of screens is not a requirement. A requirement is “a manager can approve a leave request on a phone in under a minute.” Constraints belong here too: deadline, integrations, compliance. Bad planning makes every later stage look like an engineering failure.
Design: how it will work and look
UX flows, data model, APIs, and the major technical choices. Design is not only Figma. It is also “this order cannot exist without a customer” and “this job runs asynchronously.” Review with the people who will use it. Changing a flow in a prototype is cheap. Changing it after the database is live is not.
Build: implement in slices you can see
Code the highest-risk or highest-value slice first. Keep environments close to production. Version control, code review, and a definition of done that includes tests - not “it works on my machine.” Custom software dies in giant branches. It lives in increments a stakeholder can click.
Test and release: prove it, then ship it
Unit tests for logic, integration for APIs, and real-device or browser checks for the path users take. Security and performance are part of test, not a surprise week. Release with a rollback, migrations you can reverse or expand-contract, and a store or hosting checklist. “We deployed” is not the same as “customers can use it.”
Operate and improve: the cycle does not end
Logs, uptime, crash reports, and a way to ship fixes. New requests go back to plan. Maintenance is SDLC, not a support afterthought. A product without an operate stage is a project that starts decaying on launch day. We budget for that loop so the life cycle is honest in the estimate, not only in the diagram.
