Estimating the development timeline for an API when SQL queries are ready

Estimating the development timeline for an API when SQL queries are ready involves evaluating several factors. Here's a step-by-step approach:

1. Define API Scope

• Number of Endpoints: Count how many API endpoints need to be created.
• Complexity per Endpoint: Consider if endpoints are simple (e.g., a single query) or complex (e.g., require multiple queries or custom logic).
• Authentication and Authorization: Determine if additional work is needed for securing the API.

2. Assess Development Components

• Data Layer: Since SQL queries are ready, consider if additional transformations or validations are needed before returning data.
• Business Logic: Identify if any specific computations or logic need to be applied to the data retrieved by SQL.
• API Design:
  • Standardize response formats (e.g., JSON, XML).
  • Error handling and status codes.
• Documentation: Include time for creating API documentation (e.g., Swagger, Postman).

3. Select Tools and Frameworks

• Framework Choice: The time required may vary depending on the API framework or language (e.g., Flask, Django, Express.js).
• Existing Boilerplate: If you have a starter template or boilerplate, it can save significant time.

4. Allocate Time per Endpoint

• Simple endpoints: 1–2 hours (direct query mapping).
• Medium complexity: 3–5 hours (data transformation or minor business logic).
• High complexity: 6+ hours (multiple queries, external integrations).

5. Include Testing

• Unit testing for individual functions.
• Integration testing for endpoints.
• Load testing if performance is critical.

6. Deployment and Setup

• Include time for setting up the server, deploying the API, and configuring CI/CD pipelines.

7. Buffer for Debugging

• Add a buffer of 10–20% for unforeseen issues, such as debugging or performance optimizations.

Example Timeline

Task	Time Estimate
API design (initial)	4–8 hours
Simple endpoints	1–2 hours/endpoint
Medium complexity endpoints	3–5 hours/endpoint
High complexity endpoints	6–10 hours/endpoint
Authentication setup	6–10 hours
Testing	10–15% of development time
Deployment and setup	4–8 hours

Tips for Accuracy

• Break down tasks as granularly as possible.
• Review estimates with the team (if applicable).
• Use past project timelines as references.