What is a Software Development Engineer (SDE)?

You’ve probably wondered what an SDE (Software Development Engineer) really does. It’s not just about writing code. It’s about solving problems, building solutions, and turning ideas into software that works on your phone, laptop, or browser. Whether you’re an intern or aiming for a role like Amazon SDE-2, mastering the fundamentals is key. This blog will guide you on what to expect and how to grow as an SDE, whether you’re coding daily, prepping for interviews, or working through the Striver SDE Sheet.

Table of Contents:

• Who is an SDE (Software Development Engineer)?
• Understanding the SDE Career Ladder
• SDE-1 vs SDE-2 vs SDE-3
• Eligibility and Hiring Criteria
• SDE Career Roadmap
• Becoming an SDE at MAANG
• Key Skills and Technologies
• Certifications and Projects
• Conclusion

Who is an SDE (Software Development Engineer)?

SDE stands for Software Development Engineer. They’re the ones behind the apps you use, the websites you browse, and the tools you rely on to work. They build the logic, develop features, and fix bugs that make software usable and reliable. Titles like SDE-1, SDE-2, and SDE-3 represent different levels of experience and responsibility. In this blog, you will find out what each level consists of, how to get yourself out of the present level to the next one, as well as what big tech companies (including MAANG) expect out of you.

Understanding the SDE Career Ladder: SDE-1, SDE-2, and SDE-3​

We can divide the information into three sub-sections per the level of SDE, and in each of the sections, we will discuss their respective skills required, their position and responsibilities, and the required education.

SDE-1: The Starting Point in Your Tech Career

1. Skills Required for SDE-1

Being an SDE-1 means you are either a graduate just out of college or joining the technological arena, either as an intern or on-campus placement. You’re not expected to know everything, but you should have a solid foundation in data structures, algorithms, and object-oriented programming. So, in case you have already pursued something such as the Striver SDE Sheet, you are on the right path.

You should also be comfortable with:

• One programming language, like Java, Python, C++, or Go
• Version control (Git/GitHub)
• Basic database concepts (SQL, NoSQL)
• Understanding of REST APIs and simple web architecture

2. Position and Responsibilities

Your main responsibility will be to write clean, testable, and efficient code. You will be guided by more experienced developers and may have a self-standing assignment or a small fraction of a larger piece of work. It will feel like debugging and understanding how the codebase functions, and gradually becoming a member of a development team.

It is also your responsibility to acquire knowledge regarding the product, the work process in the company, and the process of interaction between teams. You’ll likely spend time reading others’ code, writing unit tests, and deploying simple features.

3. Education Required

Most companies prefer a Bachelor’s degree in Computer Science, Engineering, or a related field, though it’s not always mandatory. Most SDE interns are turned into full-time employees with no CS degree as long as they prove they have coding, logical, and learning-thirsty abilities.

If you’re studying through Kerala University or Calicut University via a distance education basis, you can also apply for SDE-1 positions. But make sure your practical skills speak louder than your degree.

SDE-2: The Level Where You Own Bigger Problems

1. Skills Required for SDE-2

To become an SDE-2, you must level up your skills and start thinking beyond writing code. You’ll need:

• Strong command of design patterns and system design
• Deeper knowledge of the software development lifecycle
• Ability to mentor junior developers and review code critically
• Experience with tools like Docker, Kubernetes, CI/CD pipelines
• Performance optimization and debugging skills

You’re no longer just a coder, you’re becoming a builder and a problem solver.

2. Position and Responsibilities

It is here that you would own modules and features. You never wait to be told what to do, but you deliver solutions. You can create a new service, divide intricate functions, and make sure that your code can be integrated into the overall architecture.

It is also your task to observe the quality of your own and others’ codes, pull requests, and be proactive when an anomalous code or a problem appears in production. This level is reflected in the higher expectations and salaries of roles like Amazon SDE-2.

3. Education Required

Education in this case is not relevant, but rather your experience and your capability to show some impact. The chances are that you may have a traditional university background or even boot camp or open-source background, but the thing that counts is what you have built, your contribution to projects, and whether you can design solutions, not just execute them.

SDE-3: The Architect and Technical Leader

1. Skills Required for SDE-3

By the time you reach SDE-3, you’re expected to be deeply technical. Your skills should include:

• Advanced system design (distributed systems, scalability, fault tolerance)
• Leadership in architecture decisions
• Deep understanding of performance tuning, security, and data pipelines
• Strong communication with cross-functional teams and stakeholders
• Ability to mentor SDE-1s and SDE-2s at scale

You think about edge cases before they arise, and you solve problems at scale.

2. Position and Responsibilities

At this stage, you might lead the architecture of an entire product or service. Your responsibilities are not limited to writing code, but you are involved in the definition of architecture, leading planning sessions, and you may also have an impact on the product direction. You make sure that best practices are implemented in all the working teams, look over the high-impact PRs, and lead younger developers on the road to long-term technical development.

You’re expected to tackle complex challenges and make high-impact decisions on architecture and infrastructure.

3. Education Required

On this level, formal education does not really matter. The most important thing is your experience in constructing systems at scale and the extent of your success in leading tech direction. Most of the SDE-3s have 5-8 years of experience under their belts, or they can even have their master’s, but it is not a requirement. The qualifications are your output and record.

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SDE-1 vs SDE-2 vs SDE-3

If you’re planning to become a Software Development Engineer (SDE) or are currently one, and you would like to understand what distinguishes levels SDE-1, SDE-2, and SDE-3, read further. These are not titles. They are a projection of your abilities, your attitude, as well as the nature of the influence that you are supposed to make within a company.

We will examine it to make it understandable how these levels operate in the real world.

1. SDE-1: The Beginner Coder

You are new on the job as an SDE-1, and at this level, you are either a graduate or have 2 or fewer years of experience. You are concerned with taking the time to learn the codebase, efficient and clean code that is written, and knowing how a product is created inside and out.

You are assigned well-defined work. That can be fixing bugs, feature construction with clear instructions, and writing tests. You watch, you do it, and you expand. That is also the level where SDE interns are likely to be converted into full-time employees when they get it.

2. SDE-2: The Problem Solver

By the time you become SDE-2, you are not executing instructions anymore; you begin to set them. You already have experience (typically 2–5 years of experience), but actually, you are tasked with problems, not tasks anymore. It is supposed that you have to find out how to create something, divide it into pieces, delegate tasks, and guarantee quality.

You start guiding other developers who are junior to you, looking at pull requests, and your work is part of the larger scheme. You are also able to work with product managers and test engineers in order to plan releases.

The step from SDE-1 to SDE-2 is enormous, at least in terms of skills, but also in terms of ownership. Firms such as Amazon do not joke around with this jump, and Amazon SDE 2 salary and expectations prove the same.

3. SDE-3: The Tech Leader

You are an SDE-3, and now you have joined a different league. You will find it as your task to set up systems able to scale to millions of users, concerned with data flows, as well as architecture choices.

At this level, it’s less about writing code and more about defining technical direction. When the product managers want to introduce a noticeable item, they consult with you. You may not write as much code, but when you write, it is a standard that is set before others.

You also guide several engineers while establishing trade-offs concerning performance and cost, as well as deciding how systems can evolve as time progresses. An SDE-3 may even conduct interviews and affect decisions throughout the company.

The table below shows the comparison of the salaries of the top 10 companies alongside the SDE position:

Eligibility and Hiring Criteria for SDE Positions

To be able to enter into an SDE job position, one should not only be proficient in coding, but it’s also be able to meet the expectations tied to each level. Let us see the prerequisites to applying and getting chosen as SDE-1, SDE-2, and SDE-3, so you can calculate in which position you are, and how to continue.

1. SDE-1: Entry-Level Software Developer

Eligibility Criteria:

• Bachelor’s degree in Computer Science, Engineering, IT, or a related field
• Fresh graduates or up to 2 years of experience
• Good understanding of core programming concepts and problem-solving
• Some internships, personal projects, or open-source contributions are a bonus

Hiring Process:

• Online coding assessments (often hosted on platforms like HackerRank, Codility, or company portals like the Amazon SDE login system)
• Data Structures and Algorithms (DSA) round, typically focusing on arrays, strings, trees, graphs, and recursion.
• One or two technical interviews (DSA + system knowledge)
• Optional behavioral or HR round

Resume shortlisting often depends on coding practice (such as using the Striver SDE Sheet) and solid GitHub/project profiles.

2. SDE-2: Mid-Level Developer with Ownership

Eligibility Criteria:

• Minimum 2 to 5 years of professional software development experience
• Proven track record of delivering production-grade features or products
• Hands-on knowledge of object-oriented programming, SDLC, databases, and REST APIs
• Exposure to system design, testing, deployment, and debugging
• Mentoring experience or ability to review junior developer code

Hiring Process:

• Advanced coding test or take-home problem set
• Two to three rounds of technical interviews: expect questions around design patterns, low-level design, and scalable system architecture
• Leadership and ownership discussion. Interviewers want to see if you’ve taken initiative in past projects
• Companies may ask for portfolio evidence, GitHub repos, or client-facing work.
• Expect real-world scenario-based questions, such as optimizing database queries or handling latency issues.

3. SDE-3: Senior-Level Engineer and Technical Leader

Eligibility Criteria:

• Typically 6+ years of experience in software development
• Strong understanding of distributed systems, scalability, and fault tolerance
• Demonstrated leadership in solving large-scale engineering problems
• Experience in making architectural decisions and leading cross-team initiatives
• Past contributions that had a measurable business or technical impact

Hiring Process:

• Architecture and system design rounds require an in-depth understanding of data pipelines, caching, microservices, etc.
• Problem-solving and scenario-based coding rounds focused on scale and complexity.
• Managerial or leadership interviews to assess mentoring ability, tech planning, and communication
• Case studies or deep dives into past projects. Interviewers often ask about decisions you made and why

How to Transition from SDE-1 to SDE-2 and SDE-3: A Career Roadmap

Let’s now have a clear overview of the transition of an SDE.

From SDE-1 to SDE-2

1. Learn the Fundamentals, and then Soar

Your primary responsibility as an SDE-1 is to write bug-free and maintainable code. But to promote, you have to indicate that you know more than your syntax. Study the internals of the system, general design patterns, and software architecture. It is not enough to use an API, but you should know what goes on behind it. It is your thinking in terms of system design that makes a difference.

2. Build it, Then Own it.

Taking full ownership of a feature from requirements to deployment and post-release bug fixes is crucial. You’re not just writing code, you’re delivering value. Such a mindset about ownership is a good indicator that you are ready to go to the next level.

3. Become an Active Code Reviewer

You are likely to frequently have your code reviewed at SDE-1. To migrate to SDE-2, reverse that. Begin code reviewing of juniors or equals. Make constructive comments, pose the right questions, and give suggestions toward optimizations. This demonstrates technical maturity and willingness to mentor.

4. Know the Impact of the Product

Demonstrate that you not only understand how something is built but, more importantly, why it’s built. Know about product objectives, customer requirements, and business measures. Being the first one to make constructive suggestions about something beyond your scoped task is an indication that you are ready to move up to SDE-2, where business alignment becomes a more significant aspect of the job.

5. Support the Discussions of Design and Architecture

Begin to question in design meetings. Suggest improvements, propose better architectural structures, recommend indices, or highlight performance delays. Suggest appropriate indexing strategies or raise performance concerns during reviews. The more technical planning you do, the more toward an SDE-2 approach you are.

From SDE-2 to SDE-3

1. Reconsider your Practice of Going from Feature Owner to System Owner

An SDE-2 is in possession of features or modules, whereas an SDE-3 can be tasked with an entire system. To level up, seek out opportunities to assume broader ownership, e.g., be in charge of a maintained refactoring of a legacy service, take charge of a release, or develop a shared library that benefits multiple teams.

2. Build Scalable, Stable, and Secure Systems

Performance bottlenecks, data integrity, system failures, and long-term maintenance are your issues on this level. Learn concepts like load balancing, horizontal scaling, disaster recovery, and secure codes of behavior. Implement and suggest solutions that are beyond the task at hand.

3. Mentor at Scale

Mentoring isn’t just about helping a new hire fix bugs. It refers to mentoring several engineers, conducting teaching classes, and enhancing team-level standards of coding. Your technical choices begin to influence the minds of others, thinking, and coding. This is one of the key responsibilities of an SDE-3.

4. Drive Technical Planning

As a way of becoming an SDE-3, you have to drive initiatives. You may suggest a full migration to a new framework, build internal tooling to accelerate deployments, or establish a plan for architectural enhancements. You do not just code, you are a driving force of decisions and direction.

5. Speak and Act as a Leader

You require technical depth, but you will get to the top by passing the communication message. It can be as simple as writing RFCs, pitching to engineering leadership, or telling product stakeholders about a tech trade-off you may have to make, but in all cases, your job is to simplify complex concepts for everyone. This will make you someone to approach not only in your team but also in the organization.

All these steps in this journey do not just involve years of experience. It is about being able to change how you think. As long as you are ensuring that you are continuously improving your technical prowess, assisting people, and being proactive, then it will be natural for you to grow to SDE-2 and then to SDE-3.

How to Become an SDE at MAANG and Top Product-Based Companies

Breaking into top product-based companies like Google, Amazon, or Microsoft may seem intimidating. Companies such as Google, Amazon, Microsoft, or any other company that belongs to MAANG, but it’s entirely possible with the right strategy. These firms have a reputation for having high standards in recruiting Software Development Engineers (SDEs), but they’re not just looking for people who can code fast. They want engineers who know how to create efficient, scalable systems and who actually have problem-solving skills.

Your path will begin by studying data structures and algorithms well. It is a preliminary checkpoint that sieves applicants. The power to think critically and solve problems by keeping in mind optimality is excessively concentrated on online tests and initial interview stages. In case you have heard of the Striver SDE Sheet, that can be a good start since it is highly targeted to focus on your weaknesses, such as arrays, trees, graphs, and dynamic programming.

The questions that will be asked during MAANG interviews are not limited to coding. You are also supposed to know the structure of the software and the design of real-life systems. That is why you have to take time and read Low-Level Design (LLD) and High-Level Design (HLD). Firms are eager to know that you are capable of constructing the backend of a ride-sharing application or developing a fault-tolerant message queue. It’s not just theoretical, they assess how well you explain trade-offs and justify your decisions.

Building powerful projects is one of the best methods to stand out, particularly if you did not attend a Tier-1 college. GitHub or your personal portfolio are other common places that a recruiter or hiring manager would visit to have a general idea of what you are capable of. If your projects are original, solve real problems, and show that you know how to use frameworks, databases, and deployment tools, you will make an impression. The projects tend to be more effective than the certificates.

Another key piece is preparing for behavioral interviews. Companies like Amazon place heavy emphasis on their leadership principles, and they want to know if you take ownership, handle failure well, and can make small technical decisions. Practicing your communication, explaining past experiences using the STAR format, can make or break your chances, especially in the final rounds.

Now, when it comes to actually applying, don’t rely only on career portals. Instead, build your network on LinkedIn, reach out to engineers working at your dream company, and ask for referrals. Even better, participate in hackathons, open-source programs, and coding competitions where recruiters often spot emerging talent.

It’s a tough road, and it’s rarely linear. You might get rejected several times. You might feel stuck. But the key is to learn from every interview and keep building. Whether you land a role as an SDE intern or jump straight into SDE-1, the doors are always open if you come prepared with the right skill set and mindset.

To learn more about SDE, you can refer this video:

Key Skills and Technologies Required at Each SDE Level

Let’s explore the skills and technologies required to become an SDE.

SDE-1: Building Strong Foundations

At the SDE-1 level, you’re expected to have a strong grasp of programming fundamentals and the ability to write clean, efficient, and well-documented code. You should be comfortable with one or more core languages like Java, Python, C++, or Go, and understand how to work with version control systems like Git.

You’ll need to master Data Structures and Algorithms (DSA), which includes topics such as arrays, linked lists, stacks, queues, trees, heaps, graphs, sorting algorithms, and recursion. These form the basis of most interviews and will also help you write optimal production code. You’re also expected to understand the basics of object-oriented programming (OOP), error handling, and writing unit tests.

On the tooling side, familiarity with command-line tools, basic shell scripting, and using IDEs like VS Code or IntelliJ is common. You should also know how to interact with RESTful APIs, handle JSON/XML data, and make basic SQL queries.

SDE-2: Owning Systems and Deliverables

By the time you reach SDE-2, the expectation shifts from being a good coder to being a reliable contributor and partial owner of systems or services. You’ll still write code, but you’ll also review others’ code, help with system design decisions, and contribute to architectural discussions.

You need a stronger command of system design principles. Things like how a web server handles traffic, how caching works, when to use a queue like RabbitMQ or Kafka, and how to partition a database. You’ll also be using design patterns like Singleton, Observer, and Factory to write scalable and modular code.

Technology-wise, you’ll likely be working in a microservices architecture, interacting with Docker, understanding CI/CD pipelines, writing production-ready APIs, and managing relational and NoSQL databases such as PostgreSQL, MongoDB, or DynamoDB. Other expected knowledge areas include monitoring tools (like Prometheus and Grafana), cloud platforms (AWS, GCP, Azure), and Testing frameworks (JUnit, PyTest, Mocha)

SDE-3: Driving Architecture and Leadership

SDE-3 is often a technical leadership position. You’re expected to architect systems, solve business problems with technology, and guide multiple teams. You must deeply understand distributed systems, scalability, latency, security, and fault tolerance.

You’ll likely be using message queues, container orchestration tools like Kubernetes, and infrastructure-as-code tools such as Terraform or Ansible. You need a clear understanding of horizontal scaling, load balancing, rate limiting, and data replication.

Security becomes a crucial area, understanding things like OAuth, SSL/TLS, data encryption, secure data storage, authentication flows, and how to prevent common vulnerabilities (OWASP Top 10).

SDE-3s are also responsible for technical documentation, project planning, and guiding stakeholders (PMs, QAs, designers) through the technical aspects of large-scale initiatives.

Certifications and Projects That Strengthen Your SDE Resume

Conclusion

Becoming a Software Development Engineer (SDE) is a journey built on solid coding skills, system design understanding, and continuous learning. Whether you’re aiming for SDE-1, SDE-2, or SDE-3, focusing on hands-on projects, key technologies, and industry-relevant certifications will set you apart. With the right mindset and preparation, you can land roles at top tech firms and grow steadily in your engineering career.

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What is a Software Development Engineer (SDE)? – FAQs