The short version

An API engineer designs, builds, and maintains the interfaces that let software systems talk to each other: the APIs your product exposes, the integrations that connect you to other systems, and the contracts that keep both reliable. Hiring one on contract or through a vetted network lets you add this specialised capability in days, which matters most when integration or a clean API is the thing standing between you and shipping.

• Typical engagement: 3 to 12 months on contract, often tied to a specific integration or platform programme
• Day rates in Australia: A$750 to A$1,300/day depending on seniority, stack, and integration complexity
• Specialisations: REST and GraphQL API design, system integration, middleware and iPaaS, API gateways and security, event-driven architectures
• Hire one when: you need APIs designed or built, systems integrated, partner interfaces exposed, or a messy integration untangled
• Time to deploy: curated shortlists in 48 hours via Expert360
• Engagement types: contract, project-based, fractional, or interim

What is an API engineer?

An API engineer is a backend specialist focused on the interfaces between systems. They design and build the APIs that other applications, partners, and internal teams use to access your data and functionality, and they connect your systems to the third-party services you depend on. Where a general backend engineer builds whatever the server side needs, an API engineer goes deep on interface design, integration, and the reliability and security of the connections themselves.

In Australia, demand for API and integration skills runs strong, driven by the reality that most organisations now run dozens of systems that need to work together: core platforms, payment providers, CRMs, government services, and partner ecosystems. The work appears across financial services, government, retail, and any business pursuing digital transformation, where connecting systems cleanly is often the hard part. API work is usually tied to a specific stack and integration platform, and roles frequently bundle API development with .NET, Java, or Node.

The title sits alongside several related ones. The short version:

• Backend engineer: builds the whole server side; an API engineer is a backend engineer specialised in interfaces and integration.
• Integration developer: closely related, often used interchangeably, with a focus on connecting existing systems.
• Systems integration consultant: works at a higher level on integration strategy and across whole programmes, less hands-on with the code.
• Solution architect: designs how systems fit together at the design level; the API engineer builds the interfaces that realise it.

When you describe your integration or API work to Expert360, we help you pin down whether you need a hands-on API engineer or a broader integration role.

When should you hire an API engineer?

The trigger is usually that the hard part of your work is the connection between systems, or the interface other parties depend on. A contract API engineer is the right call when that work is real and time-bound.

• You need APIs designed and built. Your product or platform needs to expose clean, well-documented, versioned interfaces for a frontend, a mobile app, partners, or internal teams.
• You're integrating systems. Connecting your platform to payment providers, CRMs, ERPs, government services, or partner systems is the core of API engineering work.
• An integration has gone wrong. A brittle, undocumented, or failing integration needs someone who can diagnose and rebuild it properly.
• You're building a partner or developer programme. Exposing your platform to external developers needs APIs designed for consumption, with documentation, security, and governance.
• You're moving to microservices or event-driven architecture. Breaking a system into services makes the interfaces between them the critical work.
• You need API security and governance. Authentication, rate limiting, versioning, and a consistent API standard need someone who has done it before.

If two or more of these match, a contract API engineer is likely the right next step.

How much does an API engineer cost in Australia?

Rates vary with seniority, the stack and integration platform, and how complex the integration landscape is.

The below rates are indicative only. Experts in our network set their own rates, and you'll be able to compare real rates after requesting a talent shortlist.

Mid-level API engineer: A$750–A$950/day

Typically 3 to 6 years' experience, building and maintaining APIs and integrations in a defined stack with limited supervision. Suits steady integration delivery and extending an existing API surface.

Senior API engineer: A$950–A$1,150/day

Usually 6 to 10 years' experience, owning API design, integration architecture, and standards, and handling the security and reliability of critical connections. Suits complex integration landscapes and platforms exposed to partners.

Lead or specialist engineer: A$1,150–A$1,300/day

Deep expertise in a specific integration platform, API gateway, or high-stakes integration domain, or technical leadership of an integration programme. Government, banking, and regulated integration work sit at the top of this band.

On a fractional basis, expect roughly A$8,000 to A$17,000 per month for 2 to 3 days a week, which suits ongoing API and integration oversight without a full-time hire. Rates rise for scarce integration platforms and high-stakes domains, and ease for longer commitments.

What drives the variance:

• Integration complexity: connecting many systems or untangling a broken landscape pays above building a single clean API
• Platform and scarcity: specific integration platforms, middleware, and API gateways command a premium
• Domain: banking, government, and regulated integration work pay more
• Engagement length: longer contracts often come with a lower day rate

For comparison, a permanent API or integration engineer in Australia earns roughly A$100,000 to A$160,000 base depending on stack and level, with integration engineers averaging around A$117,000, or higher fully loaded with superannuation and on-costs. A contract engineer costs more per day but adds no on-costs, ramps fast, and ends cleanly when the work does.

API engineer vs backend engineer – what's the difference?

An API engineer is a backend engineer with a sharper focus. Here is how they differ in practice.

An API engineer specialises in the interfaces between systems: designing APIs, building integrations, and owning the contracts, security, and reliability of the connections. Their output is clean, reliable interfaces and working integrations. Day rates run A$750 to A$1,300/day. Best when the hard problem is connecting systems or exposing a well-designed interface.

A general backend engineer builds the whole server side: logic, databases, and APIs as one of several responsibilities. Best when you need broad server-side delivery rather than deep integration focus.

The practical point: for a build that is mostly application logic with some APIs, a general backend engineer is right. For work where the integration landscape is the challenge, or where your API is effectively a product that partners depend on, an API specialist pays off. Hiring a generalist for a hard, multi-system integration is the common and costly mismatch. When you describe your work to Expert360, we help you judge how much specialisation you need.

What does an API engineer actually do?

The day-to-day varies by stack and integration landscape, but most contract API engineers cover some combination of the following.

• Design APIs. Defining clean, consistent, well-documented interfaces, choosing between REST, GraphQL, or event-driven patterns to suit the use case.
• Build and maintain APIs. Implementing the interfaces and keeping them versioned and backward-compatible as they evolve.
• Integrate systems. Connecting your platform to third-party and internal systems reliably, handling the data mapping and error cases in between.
• Secure the interfaces. Implementing authentication, authorisation, rate limiting, and the controls that protect data crossing system boundaries.
• Work with gateways and middleware. Configuring API gateways and integration platforms that manage and route traffic between systems.
• Document for consumers. Producing the documentation that lets frontend teams, partners, and external developers actually use the APIs.
• Diagnose and fix. Tracing failures across system boundaries, which is some of the hardest debugging in software.

A contract engagement usually starts with a short ramp-up on the systems, data, and integration landscape, then moves into steady delivery, with a senior engineer also shaping API standards and integration architecture along the way.

How to choose the right API engineer

The real risk in hiring an API engineer is rarely whether they can write an endpoint. It is whether they design interfaces others can actually use, handle the messy reality of integrating real systems, and leave connections your team can maintain.

• API design judgement. Good API design is a skill in itself. Ask candidates to walk through an API they designed and the choices they made about structure, versioning, and consumers.
• Integration experience that matches yours. Connecting to a payment provider is different from integrating a legacy government system. Match the engineer to the kind of integration you face.
• Stack and platform fit. Match the engineer to your actual stack and any integration platform or gateway you use.
• Security awareness. Interfaces between systems are where data is most exposed. Ask how they approach API security and authentication.
• Documentation and consumer focus. An undocumented API is a liability. Ask how they make their interfaces usable by others.
• References from real integrations. A reference from an engineering lead they worked under tells you most. Ask whether the integrations they built stayed reliable.

Every API engineer in the Expert360 network is vetted for real integration and API design experience and reference-checked against the platforms and domains they claim, so the shortlist you see reflects engineers who have built connections like yours.

Frequently asked questions

What does an API engineer do?

An API engineer designs, builds, and maintains the interfaces that let software systems communicate. They design APIs, build and secure them, integrate systems with third-party and internal services, work with gateways and middleware, document interfaces for consumers, and diagnose failures across system boundaries.

What's the difference between an API engineer and a backend engineer?

An API engineer is a backend engineer specialised in the interfaces between systems: API design, integration, and the security and reliability of connections. A general backend engineer builds the whole server side, with APIs as one of several responsibilities. For deep integration work, the specialist pays off.

What is API integration?

API integration is connecting separate software systems so they can share data and trigger actions in each other, using each system's API. It is how, for example, your platform talks to a payment provider or a CRM. Building and maintaining these connections reliably is core API engineering work.

How much does it cost to hire an API engineer in Australia?

Contract API engineers in Australia typically charge A$750 to A$1,300 per day. Mid-level engineers sit around A$750 to A$950/day, senior engineers A$950 to A$1,150/day, and leads or specialists in complex integration domains A$1,150 to A$1,300/day. Banking and government integration work sits at the top.

Should I hire an API engineer or a general backend engineer?

Hire an API specialist when the integration landscape is the challenge, or when your API is effectively a product partners depend on. Hire a general backend engineer when the work is mostly application logic with some APIs. Match the choice to where the difficulty sits.

What about REST versus GraphQL?

REST is the most widely used API style and suits most needs; GraphQL gives consumers more flexibility in what data they request and suits complex, data-rich frontends. A good API engineer advises on which fits your case rather than defaulting to one. Hire for judgement, not a single technology.

How quickly can I hire an API engineer through Expert360?

Expert360 provides a curated shortlist of vetted API and integration engineers within 48 hours of you describing your needs. Because the network is pre-vetted, you can typically have an engineer engaged and starting within one to two weeks, far faster than a permanent search.

Can an API engineer work remotely?

Yes, API and integration engineering suits remote and hybrid work, and many contract engineers work this way. Some teams value on-site time for onboarding and access to internal systems, and government engagements may require on-site presence and a security clearance.