Hire the Top 3% of Freelance Integration Developers

Demand for Integration Developers Outpaces the Market

Integration developers are highly sought after for their skills in streamlining the operations and architecture of digital information systems for better performance, efficiency, and cost. In fact, the US Bureau of Labor Statistics projects that employment of computer systems analysts will grow by 10% from 2022 to 2032, well beyond the 3% average growth across all occupations. Such developers often have extensive experience across many related technologies and can help an organization avoid common pitfalls associated with fragmented technology stacks, which include impediments to collaboration and a lack of stability, scalability, and resilience.

This context presents two major challenges when hiring integration developers: first, in sourcing great candidates, and second, in effectively assessing their qualifications. Integration development is a niche skill set that can be acquired only through many years of experience on the job. It requires a deep knowledge of multiple programming and query languages along with countless software libraries, frameworks, and plugins. Some integration developers prefer to work within specific ecosystems (such as Java or .NET), while others enjoy operating across platforms and providers. How do you determine what kind of integration developer will best suit your needs?

The purpose of this guide is to mitigate these two challenges for you by helping you to better understand the role of an integration developer in your organization. We review common skills and technologies to look for, as well as how to differentiate between more- and less-experienced candidates. We also offer tips for writing an accurate job description and suggest questions to ask during the interview process to accurately gauge the candidates’ qualifications.

What Attributes Distinguish Quality Integration Developers From Others?

A skilled integration developer should be well versed in the entire software development lifecycle and possess both high- and low-level knowledge of data monitoring and analysis, API and database architecture, software testing, and DevOps. Integration developers are almost necessarily full-stack developers—engineers who are comfortable crafting both user interfaces and business logic, and who know how to efficiently control the flow of data in all directions.

While integration developers who are earlier in their careers may focus more on the specific technologies they’ve worked with, those with more extensive experience will tend to emphasize how their implementations of the relevant technologies in previous projects have led to demonstrable positive impacts on key business metrics. They understand not only how to streamline processes, but also why; they are adept at connecting the dots between the software problems to be solved and the intended business outcomes.

Regardless of your team’s needs, there are certain skills in the realm of software integration that you’ll want to look for on a candidate’s résumé to ensure a strong developer fit with respect to the everyday use cases that may arise.

Programming languages and frameworks – First, you’ll want to see proficiency (if not mastery) in at least one programming language and its corresponding frameworks and ecosystem: for example, a Python developer who’s worked with Django, Flask, and TensorFlow, or a Java developer who knows their way around Spring Boot and the Apache ecosystem. The more senior the candidate, the less important it is that they have experience in the specific ecosystem that your team operates in; an integration developer with 10 years of experience in Java and Python will have little difficulty adapting to a C# codebase, even if they’ve never written code in this language before. The fundamental skills extend well beyond the minor differences in programming syntax.

Enterprise experience – Next, look for prior experience that matches both the scale of your enterprise, as well as the complexity of the project at hand. An integration developer might need to handle sensitive data and deal with all the privacy and security concerns that come with it. Depending on the complexity, they may need to employ (or build entirely new) integration platforms to connect existing services that wouldn’t otherwise fit together neatly. These are tasks that you definitely don’t want to hand to an amateur—you’ll want to see a solid track record here.

API development – API programmers focus on how applications communicate with one another. Conventions like REST ensure that API designs follow standardized, predictable patterns, streamlining productivity for the developers who work with them. An integration developer will spend a great deal of time working with, designing, implementing, and maintaining APIs of all shapes and sizes.

Database development – Databases are the essential repositories of data that power software applications. Data management skills are crucial for most integration services. Managing data at scale can be extraordinarily complex, and sensitive data comes with serious security risks that an organization may be liable for if mishandled. A skilled integration developer will understand these risks and know what steps need to be taken to mitigate them. Beyond security, other important database skills include proper schema design and query optimization.

Testing abilities – Keep an eye out for knowledge of software testing. A Java developer who lists their experience with JUnit, for example, is signaling that they care about code quality and long-term maintainability. After all, what good is the solution if it can’t be updated in the future when bugs invariably arise? Testing helps developers find as many of those bugs as possible before the code goes live the first time.

Soft skills – Beyond the technical realm, experienced integration developers can be distinguished by their strong communication skills. As a developer gains more experience and responsibilities in their career, the role increasingly becomes about documenting solutions for other teammates (who may or may not be technically savvy) and tailoring the presentations of those solutions to meet the needs of a wide range of stakeholders—no easy feat.

Complementary Tech Skills for Integration Developers

Along with these core integration development skills, a strong candidate must have exposure to a breadth of related tools and technologies. This list describes some of the most popular programming languages and tools that an integration developer might be expected to use:

Python stands out among programming languages for its simplicity and readability, and is an excellent choice for speeding up development services. It has a robust ecosystem of popular open-source libraries, frameworks, and related tools. Python is also a versatile language that can be used in many different contexts, from data analysis to server code to web app development and beyond. This makes it a favorite of the startup world because an engineering team can run a single programming language across their entire tech stack, which streamlines maintenance.

Java is one of the most popular programming languages in the world, especially for enterprise-level software. It’s also one of the most commonly taught languages in university programs, so many computer science graduates will have hands-on experience with it. Java is an object-oriented programming language, a style that lends itself to modular software architecture with reusable components that can be integrated across different systems with relative ease. Its ecosystem is massive, and it’s been rigorously battle-tested (especially with frameworks like Spring Boot) by some of the largest organizations in the world.

JavaScript began as a front-end programming language for writing logic in web browsers, but since the advent of Node.js, the React library, and the Express.js frameworks, it has evolved into a powerful full-stack web development language in its own right. As with Python, one of the benefits of JavaScript in integration development services is that it allows you to use one programming language across the full stack of your web app, which can greatly speed up developer productivity and improve maintainability. That said, while JavaScript is ubiquitous across the internet, it isn’t used much beyond the browser or the server, so you’ll want to employ a language like Python or Java if you’re building software that’s not for the web.

C# is a popular programming language for building desktop apps, web apps, web services, and even video games. It’s favored by the same kinds of enterprise organizations that might choose Java for its massive ecosystem of tools and plugins. C# was created by Microsoft as the official language of the .NET framework, which provides all of the tools necessary to build robust desktop and web applications.

MySQL is one of the world’s most popular database management systems, built on top of Structured Query Language (SQL). It’s trusted by developers for its reliability and scalability, and preferred over other options for its ease of use when building prototypes. Most integration developers will have worked with MySQL in some capacity, though there are popular alternatives like PostgreSQL and Microsoft SQL Server that any developer may have more experience with. The underlying skills are transferable across platforms.

Apache offers top-tier web server software that dominates the market, powering nearly one-third of all websites on the internet. It’s highly customizable since it’s open source, and it’s trusted by organizations across all industries and at every scale.

Docker is a virtualization tool that enables developers to ship code in discrete packages called containers. Containerization allows for modular architecture, which can speed up developer productivity and significantly reduce compute costs for an organization when compared to more-traditional monolithic software architecture. As you might expect, this is another key area to focus on when you need integration developers for hire—because a system that uses containers must have someone on hand to ensure interoperability.

Linux is an open-source operating system for managing hardware resources like CPU and memory. The Linux command line is how developers instruct software to perform hardware actions that would be cumbersome or impossible with standard graphical user interfaces. Integration developers frequently work with command line tools, and more experienced developers will have built their own, as well.

This is just a sampling of the kinds of skills that integration developers are expected to demonstrate; there are myriad related tools and technologies and alternatives to every item on the list. What matters most are the business needs of your specific project, team, and organization.

How Can You Identify the Ideal Integration Developer for You?

To find the best integration developer for your project or organization, you must first determine the exact job requirements (manage data analysis, develop integration architectures, etc.).

Defining Your Needs

Consider the “North Star” for this role: Is it to cut costs or to drive revenue? Is the project client-facing or for internal purposes? Will the developer be working as an individual contributor or will they have direct reports? Does your company use legacy software or cutting-edge technologies? Knowing the answers to these kinds of questions before you begin the hiring process will help you to narrow your focus and, as a result, source the ideal prospects. It may also help to consider gaps in your existing team’s so that you can then try to fill them with someone who has prior experience in those areas. Conduct thorough reference checks to assess past project success.

Balancing Budget and Expertise

It’s no secret that the top talent in software engineering can command a considerable sum for their labor, and this price only goes up as the engineer masters their craft and gains exposure to the full range of integration platforms and services available. Thankfully, high-quality integration developers can offset their fees several times over in the form of costs cut or revenue generated for the business.

Consider the complexity of the task at hand: Is the technology popular and well documented? How much of this system will need to be designed and built from scratch? Is seamless programmer onboarding a top priority, or can you afford to spend more time and resources on onboarding? The more complex the project, the more likely you’ll need the professional services of a senior talent. For example, if you need someone to maintain an existing system on a team with senior leadership, it may be enough to hire a junior or mid-level developer; if that system requires serious architectural upgrades, and there’s nobody on the development team with the skills or bandwidth to tackle them, then you’ll need an expert in this field. How can you distinguish between junior, mid-level, and senior developers?

A junior integration developer typically has one to two years of experience with a single programming language. They’ve worked on some simple integration tasks like REST API integration but most likely need guidance and support from more experienced colleagues to complete projects.

A mid-level integration developer usually has three to five years of experience and has worked in more than one programming language. When provided with the technical specifications for a project, they can implement it independently. They should be capable of contributing technical opinions, as well as reviewing code from junior engineers.

A senior integration developer typically has at least five years of experience and has worked with a wide range of programming languages. They can propose solutions for complex tasks based on their direct experiences on projects that require deep technical knowledge, such as SSO, subscription payment integration, and authentication and authorization with third-party providers. They should have the depth of technical knowledge to review code written by any of their colleagues and the top-notch communication skills required to coach more-junior engineers to level-up their skills. Conducting reference checks for senior-level engineers is especially important to assess their leadership and mentorship abilities.

What are the most frequent use cases for an integration developer?

Integration developers are instrumental in a variety of scenarios where information systems need to be able to communicate. Their professional service is particularly sought after in the following typical use cases:

• Enterprise application integration – Integrating enterprise applications such as CRM, ERP, and SCM systems to ensure seamless data flow and communication among them
• Data integration – Merging data from different sources, such as databases, cloud storage, and third-party APIs, into a unified data warehouse, to aid in decision-making and analytics
• Cloud integration – Connecting cloud-based services with on-premises applications—something that’s becoming increasingly important as many businesses move toward cloud computing while still relying on legacy systems
• API development and management – Creating and managing APIs to enable different applications to communicate effectively, following best practices like REST or SOAP; strong API programmer backgrounds are needed for this use case
• Microservices architecture implementation – Helping organizations transition to a microservices architecture, improving modularity and making the application easier to understand, develop, test, and scale
• B2B (business-to-business) integration – Facilitating the flow of data between businesses, such as supply chain management and automation, to enhance collaboration and streamline transactions

Each of these use cases highlights the diverse and critical role integration developers play in modern organizations, making them an invaluable asset to any business seeking to optimize their infrastructure. If your hiring process focuses on one of these use cases, look for candidates with the corresponding background (e.g., a cloud integration developer should be familiar with cloud security practices and cloud service providers, such as AWS, Azure, and GCP).

How to Write an Integration Developer Job Description for Your Project

When writing a job description for an integration developer, it’s common to place too much emphasis on the required tools and technologies (and years of experience with each). Instead, base your job requirements on the business objectives of hiring for this role. As discussed, an experienced Java developer, for example, will be able to jump into a C# codebase without much friction. You’re far more likely to attract top talent if you can pique their interest with the kinds of problems they’ll be tasked with solving.

In addition, consider the project duration and whether you seek a full-time, part-time, or dedicated developer. You may include how many weeks you expect the engagement to last as well, as how many hours per week your developer will work.

What Are the Most Important Integration Developer Interview Questions?

As with writing the job description, when you’re interviewing integration developers, you should try to assess their problem-solving skills and their ability to tackle novel tasks—and put more weight on those skills over the number of tools they have under their belt. Here are some ideas for questions to ask, along with the desirable answers to expect:

What does an integration developer do?

You may start with this basic question to weed out candidates and gain insight into a developer’s area of specialization. Integration development encompasses a wide range of duties related to information systems, including data management and analysis, API design and ongoing maintenance, and the means by which systems communicate with one another. A strong candidate will be able to discuss the flow of data through and between systems, and speak at length about topics like performance, reliability, maintainability, scalability, and security. They should have a firm grasp of the tools available on the platforms they’ve worked with. The most experienced integration developers will be conversant in the architecture of distributed systems, which requires serious considerations and future-proofing measures to ensure long-term maintainability.

Can you describe a challenge you faced in the past with a platform or service you were trying to integrate into an existing system and how you solved it?

This question aims to assess the candidate’s problem-solving abilities. A strong candidate will be able to speak about their ability to extract information from various resources such as third-party documentation and online articles, and to combine it with their own skills and experiences to formulate effective solutions. A well-rounded integration engineer should possess robust technical skills akin to those of a full-stack developer, so listen for answers that describe end-to-end solutions. Candidates should demonstrate a comprehensive understanding of the platform they work on and an ability to quickly pick up new technologies and integrate them into their existing skill set.

What can you tell me about your prior experiences in maintaining the security of the data you work with?

Data security is a critical area for an integration developer to master because failures in cybersecurity could lead to serious liabilities for their employer. Invite the candidate to dig into the nitty-gritty of the systems they’ve worked with in the past, and listen for their experiences with encryption, authentication, and the specific protocols and tools they’re familiar with. A skilled integration developer will be happy to get into the details and describe their solutions.

Can you tell me about a time when you had to explain a complex technical issue to a nontechnical stakeholder?

The work of software integration is often quite “deep in the weeds,” as engineers would say, and any engineer can tell you that if you spend too much time in the weeds, you’ll start to lose track of the real world. That can make it a challenge for highly experienced developers to effectively communicate with nontechnical team members and stakeholders who aren’t familiar with their jargon. Look for candidates who express empathy and patience with colleagues, and who make it a priority to tailor their messages to ensure buy-in from nontechnical stakeholders.

Why Do Companies Hire Integration Developers?

Data powers our world in the modern era, and integration developers are crucial for maintaining the flow of data through an organization and its software. Modern tech stacks at enterprise organizations are often composed of so many moving pieces that no one person on a team fully understands how they all fit together, but it’s the integration developer’s job to ensure the interoperability of all those pieces and to constantly seek ways to streamline business operations.

This becomes all the more important as a company grows and scales. A highly skilled integration developer can be a key strategic partner on your team who can lead initiatives to cut costs and drive revenue at a scale that dwarfs their annual salary. Any organization that’s made it past the MVP and PMF stages of the development process would be wise to bring in an integration developer well before they begin to feel the pains of not having one.