What are the main use cases for LLMs?

Large language models (LLMs) are versatile tools with several practical applications in software development and technical workflows. Their ability to process and generate human-like text makes them useful for automating tasks, enhancing productivity, and solving specific problems. Below are three key use cases, explained with concrete examples relevant to developers.

First, LLMs excel at text generation and code assistance. For instance, tools like GitHub Copilot use LLMs to suggest code completions, draft documentation, or generate boilerplate code based on context. Developers can describe a function in plain English (e.g., “sort a list of users by last login date”), and the model can output valid code snippets in languages like Python or JavaScript. LLMs also help create content for user-facing features, such as auto-generating product descriptions, chatbot responses, or email templates. This reduces repetitive work and lets developers focus on complex logic.

Second, LLMs are effective for information retrieval and analysis. They can parse large volumes of text, extract key details, or summarize technical documents. A developer might use an LLM to scan API documentation and return a concise explanation of an endpoint’s parameters. Similarly, LLMs can analyze logs or error messages to identify patterns—for example, grouping similar bugs from a crash report or highlighting common issues in user feedback. This capability is also leveraged in question-answering systems, where an LLM-powered tool could answer internal technical queries (e.g., “How do we handle authentication in our microservice?”) by referencing internal wikis or code comments.

Finally, LLMs enable task automation and specialized workflows. They can convert unstructured input into structured formats, such as turning a user’s natural language request (“Book a meeting with the team next Thursday at 2 PM”) into a calendar event API call. In testing, LLMs can generate synthetic data or simulate user interactions for QA. For example, a model could create realistic test cases for a form validation feature by producing varied combinations of valid and invalid inputs. LLMs also power tools that translate between languages or frameworks, like converting a SQL query into a MongoDB aggregation pipeline based on a schema definition.

These use cases demonstrate how LLMs can streamline development tasks, reduce manual effort, and solve specific technical challenges. By integrating them into workflows—through APIs, plugins, or custom tools—developers can enhance productivity while maintaining control over implementation details.