Custom software development involves the development of customized software solutions for the fulfillment of some unique needs of businesses or organizations. Contrary to readymade off-the-shelf solutions, the custom software solutions are either developed from scratch or modified on a large scale with the intent of meeting certain workflows and objectives.

The advantage with custom software is that it was more or less developed for explicit business processes in mind. It allows room for flexibility and probably opportunities to grow with your changing needs. It's also competitive because it features integrations unique to your organization, which might or might not be given by off-the-shelf software.

That depends on such factors as project complexity, the scope of the features, besides the methodology that has been used in order to apply the development process. That can take anywhere between a number of weeks to as much as several months at large. If only there had been a detailed elaborated project plan with clear requirements, it would be great, in order to provide an exact idea about the timeline.

General steps in a cycle of custom software development include requirement gathering and analysis, design and prototyping, development/coding, testing/quality assurance, deployment, and support/maintenance. Each stage, in its own way, is an assurance that your needs and expectations will be met with the final product.

It achieves this through vigorous testing: unit testing, integration testing, and user acceptance testing. Other best practices that keep your software safe against vulnerabilities and running at peak performance in software development include secure coding techniques, periodic security audits.