Hire Backend Developer in Sri Lanka
Build scalable, secure, and high-performance backend systems with an experienced Senior Software Engineer specializing in modern API architecture and cloud-native development.
Short answer: to hire a good backend developer, test the things that fail in production: API contract design, data modelling and indexing, transactions and concurrency, and how the candidate debugs a slow or failing endpoint. A two-hour practical exercise plus a structured technical conversation will tell you more than any number of résumé keywords.
Key takeaways
- Screen in three stages: written questions, a practical API/database exercise, and a design conversation.
- Ask about idempotency, transactions, indexes and pagination: they separate experienced backend engineers from framework users.
- Have candidates read a query plan or a slow-endpoint trace; debugging skill matters more than syntax.
- Check operational habits: logging, metrics, migrations and rollback plans.
- Budget and engagement model come first; see the linked cost guide before you shortlist.
If you are looking to hire a backend developer in Sri Lanka, you need someone who understands scalability, system architecture, and production-grade engineering practices. Backend systems power your product — from authentication and APIs to database operations and infrastructure automation.
Why Hire a Backend Developer from Sri Lanka?
Sri Lanka has become a growing technology hub with highly skilled software engineers working with international startups and enterprise platforms.
- Strong technical education background
- Experience with global remote teams
- High-quality engineering standards
- Cost-effective development solutions
Backend Expertise & Technical Stack
As a Senior Software Engineer focused on backend work, I specialize in:
- Node.js & Express backend development
- RESTful API architecture & microservices
- Database design (MySQL, PostgreSQL)
- Redis caching & performance optimization
- Authentication & role-based access control
- AWS cloud deployment & DevOps workflows
A strong backend is invisible to users — but critical to product success.
Scalable Architecture Approach
I design backend systems that support:
- Horizontal scalability
- Stateless API services
- Load-balanced deployments
- Database read replicas
- Secure infrastructure configuration
Who Should Hire Me?
- Startups building MVPs
- SaaS companies scaling infrastructure
- Businesses modernizing legacy systems
- Founders needing reliable backend architecture
Remote Collaboration & Delivery
I work remotely as a Senior Software Engineer for Decryptogen LLC, a US-based company, and previously delivered software for Sweden-based clients at Wenthura Solutions. That means clear written communication, agile workflows, and production-ready deployments across time zones. From planning architecture to CI/CD integration, projects are delivered with stability and long-term maintainability in mind.
How to vet backend skills: a three-stage process
Backend work is mostly invisible in a demo, so you have to test it deliberately. This is the sequence I would use for any backend role, whether the stack is Node.js, Java or Python.
- Written screen (30 minutes, async). Five short questions about past systems: largest table they managed, worst production incident, how they handled a breaking API change. Written answers also test remote communication.
- Practical exercise (2–3 hours, paid if longer). Build or extend a small API with one tricky requirement, such as preventing duplicate payments or paginating a large list consistently.
- Design conversation (45–60 minutes). Walk through scaling and failure modes of the exercise or of a system close to your product.
API design questions that reveal experience
Good backend developers think about the contract before the code. Ask questions that have trade-offs, and listen for reasoning rather than a single correct answer. The REST API design guide covers the underlying principles in more depth.
- "A client retries a POST after a timeout. How do you make sure the order is not created twice?" Look for idempotency keys and a unique constraint, not "the frontend disables the button."
- "How do you paginate a feed of 50 million rows that changes while users scroll?" Cursor-based pagination beats OFFSET here; strong candidates explain why.
- "You need to rename a field used by three mobile app versions. What is your plan?" Expect additive changes, deprecation windows and versioning only when necessary.
- "What status code and body do you return for a validation failure versus a permission failure?" Consistent error shapes are a sign of maturity.
A short idempotency example is a useful discussion prompt:
-- One row per client-supplied idempotency key
CREATE TABLE payment_requests (
idempotency_key TEXT PRIMARY KEY,
order_id BIGINT NOT NULL,
status TEXT NOT NULL,
response_body JSONB,
created_at TIMESTAMPTZ NOT NULL DEFAULT now()
);
-- Handler: try to claim the key; if it already exists, return the stored response
INSERT INTO payment_requests (idempotency_key, order_id, status)
VALUES ($1, $2, 'processing')
ON CONFLICT (idempotency_key) DO NOTHING
RETURNING idempotency_key;Ask the candidate what happens if the process crashes between claiming the key and calling the payment provider. Strong answers mention status transitions, a reconciliation job, and the provider's own idempotency support.
Database questions worth asking
Most backend performance problems are data problems. These questions quickly show whether a developer understands the database or just the ORM. For background, see database design for scalable applications.
| Topic | Question | What a strong answer includes |
|---|---|---|
| Indexes | "Which index would you add for WHERE tenant_id = ? ORDER BY created_at DESC LIMIT 20?" | Composite index (tenant_id, created_at); mentions reading EXPLAIN output |
| N+1 queries | "This endpoint makes 201 queries. Why, and how do you fix it?" | Eager loading or batching; measures before and after |
| Transactions | "Two users book the last seat at the same time. What happens?" | Row locks, SELECT ... FOR UPDATE, or a constraint; knows isolation levels |
| Migrations | "How do you add a NOT NULL column to a 100M-row table?" | Expand/contract: add nullable, backfill in batches, then enforce |
| Caching | "When would you not add Redis?" | When the query can be fixed, or invalidation cost outweighs the gain |
Signals versus red flags
| Green flag | Red flag |
|---|---|
| Talks about failure modes unprompted | Only describes the happy path |
| Measures (logs, traces, EXPLAIN) before optimising | Adds caching or microservices as a first move |
| Explains why a past design was wrong | Every past project was "perfect" |
| Writes tests around business rules | Tests only that controllers return 200 |
| Asks about data volume and SLAs | Jumps straight to framework choice |
Operational habits to check
A backend developer you can leave alone with production should be able to describe, in concrete terms, how their code is deployed, observed and rolled back. Ask them to sketch their last CI/CD pipeline, name the three metrics they would alert on for an API (error rate, latency percentiles, saturation), and explain how they would trace one slow request across services. The backend architecture best practices post lists the defaults I expect on any production system.
For my own background: I built Spring Boot and Kafka services against Oracle and Informix databases at Mobitel, and currently work on Node.js, Spring Boot and Python backends with PostgreSQL and MongoDB at Decryptogen. If you want help scoping a Java backend specifically, the Java and Spring Boot development service explains how I work.
Budget and engagement
Rates vary widely with seniority and engagement model, so settle that before you screen. The guide on how much it costs to hire a software developer in Sri Lanka breaks down typical ranges and the hidden costs of each model.
FAQ
How long does it take to hire a backend developer in Sri Lanka?
With a focused process (written screen, practical exercise, design call), one to three weeks from first contact to start date is realistic for a contractor. Full-time hires with notice periods take longer.
Should the technical exercise be paid?
If it takes more than about two hours, yes. Paying for longer exercises attracts experienced candidates who would otherwise decline unpaid take-home work.
Node.js or Java for my backend?
Node.js suits I/O-heavy APIs and teams already using TypeScript. Java with Spring Boot suits complex domain logic, strict transactional needs and enterprise integration. Hire for the stack you will maintain long term.
What is the most revealing single backend interview question?
Ask how they would prevent a duplicate payment when a client retries a request. It touches API design, database constraints, failure handling and third-party integration in one question.
Can a backend developer also handle DevOps?
Many senior backend engineers can run CI/CD, containers and basic cloud infrastructure. For complex multi-account cloud setups or strict compliance, consider a dedicated DevOps or platform engineer.
Let’s Build Scalable Systems
If you’re ready to hire a backend developer in Sri Lanka who understands performance, security, and scalability — let’s discuss your project requirements.
I’m Sandaruwan Jayasundara — Senior Software Engineer | Backend Specialist. Visit sandaruwan.dev to explore my work and get in touch.