Backend Developer Job Description

Key skills

Responsibilities

• • Design and implement scalable RESTful or GraphQL APIs consumed by frontend and mobile clients
• • Model and optimize relational and non-relational database schemas for performance and integrity
• • Build background job systems and event-driven pipelines for asynchronous processing
• • Implement authentication flows including OAuth2, JWT, and session management
• • Write integration and contract tests to maintain API backward compatibility
• • Instrument services with structured logging, metrics, and distributed tracing
• • Review infrastructure requirements and collaborate with DevOps on deployment patterns
• • Participate in on-call rotation, investigate incidents, and document post-mortems

Requirements

• • 3+ years building production server-side applications in a statically or dynamically typed language
• • Strong relational database skills including schema design, indexing strategy, and query tuning
• • Demonstrated experience designing and versioning public-facing APIs
• • Solid understanding of security best practices: input validation, secrets management, OWASP top 10
• • Familiarity with containerization and deploying services in a cloud environment
• • Experience diagnosing production issues using logs and metrics tooling

Nice to have

• • Experience with event-driven architectures using Kafka, RabbitMQ, or AWS SQS/SNS
• • Knowledge of NoSQL data stores (MongoDB, DynamoDB, or Cassandra) and their tradeoff profiles
• • Exposure to database migration tooling and zero-downtime deployment strategies
• • Open-source contributions to backend frameworks or infrastructure tooling

What to look for in a great Backend Developer

Strong backend engineers think about the operational lifecycle of a system, not just whether it works in development. Look for candidates who ask about read/write ratios, expected data volumes, and failure modes before they start designing. They should understand the difference between eventual and strong consistency, and know when each matters. Ownership of reliability — instrumenting services, participating in on-call, writing durable fixes rather than quick patches — is a distinguishing trait of senior candidates. API design instinct, especially around versioning and backwards compatibility, is a practical differentiator.

Interview questions to ask a Backend Developer

Ask the candidate to design a rate-limiting system or a job queue from scratch — observe how they reason about concurrency and failure modes. Walk through a schema design problem and listen for questions about cardinality, indexing, and future extensibility. Ask how they would debug a latency spike in a production API; good candidates will describe a hypothesis-driven approach using metrics and traces. Finally, ask about the hardest data consistency bug they've encountered — this uncovers practical, hard-won database knowledge that textbooks rarely teach.

Where to source Backend Developers

GitHub repositories for popular server frameworks and database libraries surface active contributors. LinkedIn and tech-specific boards work well when filtered by language and framework. Backend-focused newsletters, podcasts, and Slack communities attract practitioners who invest in staying sharp. For senior hires, look for engineers who have spoken at conferences or published technical writing — it signals depth and communication ability. Referrals from your existing backend team are especially high-signal, since engineers tend to know the technical quality of their peers' work directly.