Build APIs for System Communication

The Problem Isn't the Data. It's the Conversation Your Systems Can't Have.

You've got a CRM. You've got an operations platform. You've got a customer portal. Each of them holds important business data. And every day, someone on your team is the human router — copying records from one system into another, manually triggering actions that should happen automatically, and reconciling discrepancies that wouldn't exist if the systems could just talk to each other.

APIs are how software systems communicate. A well-designed API is the difference between a digital ecosystem that runs itself and a collection of tools that require constant human glue. At NICKTUNG, building APIs for system communication is one of the core things we do — and we do it with the rigour that makes the difference between an API that works in production and one that causes problems the moment traffic or complexity increases.

What Goes Into a Well-Built API

Most developers can build an API that works. Fewer build one that works well under the conditions production actually creates: high concurrency, unexpected payloads, downstream failures, and clients that don't always behave as documented.

Here's what NICKTUNG brings to API development:

• Clear, consistent resource design — RESTful conventions applied properly, with predictable URL structures and HTTP semantics that make the API intuitive to consume
• Authentication and authorisation — OAuth 2.0, API keys, JWT tokens, or service-account patterns, implemented correctly rather than bolted on as an afterthought
• Rate limiting and throttling — protecting your systems from abuse and runaway clients without breaking legitimate consumers
• Versioning strategy — so you can evolve your API without breaking existing integrations, with a deprecation path that gives consumers time to migrate
• OpenAPI/Swagger documentation — machine-readable specs that let other developers (and your own future team) integrate quickly without guesswork
• Comprehensive error handling — meaningful error codes and messages that tell consumers exactly what went wrong and what to do about it
• Idempotency — critical for operations involving payments, order creation, or any action that should only happen once even if the request is retried

When You Need a Custom API vs. Using Third-Party APIs

Not every integration requires building a custom API. Sometimes the right answer is connecting two existing platforms using their published APIs, which we also do. But there are scenarios where you need a custom API:

• Your internal systems don't have APIs, but other platforms need to talk to them
• You need to aggregate data from multiple sources into a single, clean interface
• You're building a product that other developers or partners will integrate with
• You need to expose specific business capabilities without exposing your entire internal system
• You're migrating off a legacy platform and need to maintain a stable interface during the transition

We help you scope this correctly — building custom APIs where they add value and using existing ones where they're fit for purpose. The goal is always the right solution for your business, not the most technically interesting one.

API Gateway, Security, and Singapore Data Compliance

Every API that carries personal data has PDPA obligations. This is especially important for APIs that serve multiple downstream consumers — a breach or misconfiguration doesn't just affect one system, it affects everything connected to that API.

NICKTUNG designs APIs with security built in from the start:

• Input validation that prevents injection attacks at the API boundary
• Transport encryption (TLS 1.2+) with certificate pinning for sensitive integrations
• Scoped authorisation — consumers can only access the data they're entitled to
• Audit logging that satisfies PDPA accountability requirements
• Rate limiting and IP allowlisting where appropriate for sensitive data endpoints

For businesses with multiple APIs, we also implement API gateway patterns that centralise authentication, logging, and rate limiting — reducing the surface area for security issues and simplifying the operational overhead of running multiple services.

EDG Grants for API Development

Custom API development that builds new business capabilities often qualifies for Singapore's Enterprise Development Grant (EDG), which co-funds up to 50% of project costs. API projects we've scoped for clients typically range from S$20,000 to S$100,000 depending on complexity.

We help you build a strong EDG application by documenting the business capability being created, the expected productivity improvement, and the technical approach — in the language assessors are looking for.

What Happens After the API Is Built

An API is not a finished product the day it ships. It's the start of an ongoing relationship between your systems, your team, and potentially your partners or clients. NICKTUNG builds for what comes after launch:

• Versioned endpoints so you can evolve without forcing immediate migration on consumers
• Monitoring and alerting so you know when error rates spike before your consumers report problems
• Load testing before go-live so you know your API can handle the volumes you're expecting
• Developer documentation thorough enough that onboarding a new integration partner doesn't require a phone call

Frequently Asked Questions

Should we build a REST API or a GraphQL API?

REST is the right choice for most B2B integrations and internal system communication — it's widely understood, well-tooled, and easy to version. GraphQL makes sense when you have many different consumers with different data needs (like a public platform with multiple client types) and you want to avoid over-fetching. We recommend based on your specific use case, not current trends.

How do you handle breaking API changes when downstream systems are already using the API?

We implement versioned APIs (e.g. /v1/, /v2/) and maintain old versions with documented deprecation timelines. We communicate changes clearly to all consumers before deprecating. In most cases, a well-designed v1 can be extended without a breaking change for 2–3 years before a v2 becomes necessary.

We have a legacy system with no API. Can you add one without replacing the whole system?

Yes. We frequently build API layers on top of legacy systems — reading from and writing to the legacy database or existing application layer without touching the core system. This is often the right first step before a full modernisation, as it lets you start integrating immediately while the longer-term rebuild is planned.

If your systems can't communicate cleanly, your business is carrying unnecessary overhead every single day. Talk to NICKTUNG — we'll design an API architecture that makes your digital ecosystem work the way it should.