To land a job in a product-based company, you generally need to be proficient in a few key domains:

1. Core Domains:

• Data Structures and Algorithms (DSA): Essential for problem-solving and technical interviews.
• System Design: Important for understanding how different parts of a system work together.
• Object-Oriented Programming (OOP): Fundamental for software development.

2. Technical Skills:

• Front-End Development: HTML, CSS, JavaScript, and frameworks like React or Angular.
• Back-End Development: One or more back-end languages (e.g., Python, Java, Node.js) and knowledge of databases (SQL and NoSQL).
• Full Stack Development: A combination of front-end and back-end skills.
• Mobile App Development: Swift for iOS, Kotlin or Java for Android.
• DevOps: Understanding of CI/CD pipelines, tools like Docker, Kubernetes, Jenkins, etc.

3. Languages to Learn:

• The choice of programming language can depend on the company's tech stack, but Java, Python, and JavaScript are commonly sought after due to their widespread use in the industry.

To prepare for roles in product-based companies, focus on mastering the skills relevant to the specific job roles you're interested in, build a strong foundation in DSA and system design, and work on real-world projects to demonstrate your capabilities. Also, engage with the tech community, contribute to open-source projects, and keep up with industry trends.