Best 20+ Tools for Backend Software Engineers in 2025

MailerSend is a cloud-based email service that focuses on sending emails automatically from your apps or websites. Unlike regular email services for marketing campaigns, MailerSend specializes in sending individual messages triggered by user actions.

Resend is an email API service that helps developers send emails from their applications. Think of it as the delivery system for your app's emails - whether that's password resets, welcome messages, or marketing campaigns.

DeveloperHub is a complete documentation tool that combines writing, publishing, and tracking in one place. You can create different types of content including API references, how-to guides, release notes, and knowledge bases all in the same project.

DeepDocs is a GitHub AI agent that maintains your technical documentation in perfect sync with your codebase. When you commit code changes, it scans your entire repository to find documentation that needs updates and makes the necessary changes automatically.

Fern is a platform that automatically generates SDKs and API documentation from your API definition. You provide your OpenAPI, AsyncAPI, or gRPC specification, and Fern creates ready-to-use client libraries in languages like TypeScript, Python, Go, Java, Ruby, C#, PHP, and Swift.

Speakeasy is a complete API toolchain that transforms your OpenAPI specification into ready-to-use developer tools. It creates native SDKs that follow best practices for each programming language, making them feel handwritten rather than machine-generated.

Bump is an API documentation tool that creates beautiful documentation from your OpenAPI or AsyncAPI files. Instead of writing documentation by hand, you provide your API specification file, and Bump generates a complete documentation website with all endpoints, parameters, and examples.

Stoplight is a web-based platform for API design and management that follows a design-first philosophy. This means you plan and design your API before writing any code, which saves time and reduces errors during development.

Scalar is a platform for building API documentation that looks professional and works smoothly. You provide your OpenAPI document, and Scalar transforms it into easy-to-read pages with examples and testing tools built in.

Better Auth is a framework-agnostic authentication library that runs directly in your application. It handles user accounts, login sessions, and security features without relying on external services. You keep full control of your user data because everything runs on your own database and server.