Overview
APIs are the connective tissue of modern software—they enable communication between your frontend and backend, power mobile apps, integrate with third-party services, and increasingly serve as products themselves. Hiring for API development requires engineers who think beyond just "making it work" to "making it intuitive and reliable."
The best API engineers combine strong backend skills with an almost product-minded approach to design. They obsess over consistent naming conventions, thoughtful error messages, and documentation that actually helps developers succeed. They understand that an API's "user interface" is its contract—and a bad interface creates frustration that ripples across every team consuming it.
Whether you're building internal APIs that connect microservices, partner APIs for B2B integrations, or public APIs that external developers depend on, the hiring bar is similar: you need engineers who care deeply about the developers on the other side of their endpoints.
What Success Looks Like
Before you start hiring, understand what a successful API initiative looks like. Your API engineering efforts should produce tangible results within the first 90 days—not just working endpoints, but well-designed ones that accelerate development across your organization.
Signs You Made the Right Hires
Technical Excellence
- Delivers consistent, predictable API responses across endpoints
- Implements proper authentication and authorization patterns
- Designs clear error responses that help consumers debug issues
- Creates APIs that remain stable as requirements evolve
- Writes comprehensive documentation alongside implementation
Design Sensibility
- Uses intuitive naming conventions consistently
- Structures resources and endpoints logically
- Thinks about versioning strategy from the start
- Balances RESTful purity with pragmatic usability
- Considers pagination, filtering, and search patterns early
Developer Experience Focus
- Tests APIs from the consumer's perspective
- Provides clear, actionable error messages
- Creates examples and sandbox environments
- Responds thoughtfully to integration feedback
- Builds tooling that makes consumption easier
Strategic Thinking
- Anticipates future use cases in current design
- Identifies opportunities for consolidation or standardization
- Communicates breaking changes with clear migration paths
- Balances consistency with performance requirements
- Documents design decisions for future maintainers
Red Flags in the First 90 Days
If you see these patterns, address them immediately:
- Inconsistent response formats across endpoints
- No consideration for backward compatibility
- Documentation that's out of sync with implementation
- Error messages that expose implementation details
- Authentication implemented as an afterthought
- No versioning strategy or plan for evolution
- Endpoints designed around internal data models, not consumer needs
- Performance problems under basic load
Roles You'll Need
The Core API Team
Building APIs well requires a specific combination of skills. Here's how to structure your team based on project scope.
Small API Project (2-3 engineers)
| Role | Focus | Why Needed |
|---|---|---|
| Senior Backend Engineer | Architecture, core implementation | Sets patterns and standards |
| Mid-level Backend Engineer | Feature endpoints, testing | Executes on established patterns |
| Part-time Technical Writer | Documentation | Ensures documentation quality |
Medium API Initiative (4-6 engineers)
| Role | Focus | Why Needed |
|---|---|---|
| API Architect/Lead | Design standards, review, strategy | Ensures consistency at scale |
| Senior Backend Engineers (2) | Domain-specific API areas | Deep expertise in different domains |
| Mid-level Backend Engineers (2) | Implementation, testing, tooling | Executes and builds infrastructure |
| Technical Writer | Documentation, examples | Developer experience focus |
Large-Scale API Platform (7+ engineers)
Add: DevOps/Platform Engineer for API infrastructure, Developer Advocate for ecosystem engagement, and dedicated QA for API contract testing.
What to Look for in API Engineers
Essential Traits
- Contract-first thinking: Designs the interface before implementation
- Empathy for consumers: Considers how others will use the API
- Documentation mindset: Writes docs as part of development, not after
- Versioning awareness: Plans for change from day one
- Security consciousness: Bakes in auth/authz properly
Technical Skills by Seniority
| Level | Expected Skills |
|---|---|
| Junior | Can implement endpoints following established patterns; writes tests |
| Mid | Designs resource models; handles auth; implements pagination/filtering |
| Senior | Defines API standards; makes REST vs GraphQL decisions; mentors |
| Staff | Sets organization-wide API strategy; defines governance |
REST vs GraphQL: Making the Right Decision
This is one of the most consequential decisions in API development. Hire engineers who understand both approaches and can make pragmatic choices.
When REST Makes Sense
Choose REST when:
- Building public APIs for broad adoption (more developers know REST)
- API will be consumed by many different clients over time
- Caching is critical (HTTP caching works naturally)
- Operations are CRUD-focused and resource-oriented
- Team has strong REST experience
- You need fine-grained access control per endpoint
REST Strengths:
- Universal familiarity among developers
- Excellent HTTP-level caching
- Simple to document with OpenAPI/Swagger
- Stateless by design
- Easy to version explicitly
When GraphQL Makes Sense
Choose GraphQL when:
- Multiple frontend teams with different data needs
- Mobile apps need to minimize over-fetching
- Building for a single product with tight frontend-backend collaboration
- Rapid iteration on data requirements expected
- Team has GraphQL experience and tooling
GraphQL Strengths:
- Clients request exactly what they need
- Single endpoint simplifies some aspects
- Strong typing catches errors early
- Excellent for complex, nested data
- Built-in introspection
Hiring Implications
For REST APIs, prioritize candidates with:
- Strong HTTP protocol understanding
- Experience with OpenAPI/Swagger documentation
- Understanding of caching strategies
- RESTful design principles (resource-oriented thinking)
For GraphQL APIs, prioritize candidates with:
- Schema design experience
- Resolver optimization skills
- N+1 query prevention knowledge
- Federation experience (for larger systems)
Important: The best candidates understand both paradigms and can articulate trade-offs. Be wary of engineers who are dogmatic about one approach.
Team Structure and API Governance
Centralized vs Distributed API Development
Centralized Model
- Dedicated API team owns all API development
- Ensures consistency but can become a bottleneck
- Best for: smaller organizations, public API products
Federated Model
- Domain teams own their APIs within standards
- API platform team provides tooling and governance
- Best for: larger organizations, microservices
Hybrid Model
- Core API team sets standards and owns critical paths
- Domain teams implement within guidelines
- Best for: growing organizations transitioning to scale
API Governance in Practice
Regardless of structure, establish these early:
Design Standards
- Naming conventions (snake_case vs camelCase)
- URL structure patterns (/v1/users vs /users?version=1)
- Error response format (standardized error objects)
- Pagination approach (cursor vs offset)
Review Process
- API design review before implementation
- Breaking change approval workflow
- Deprecation timeline requirements
Documentation Requirements
- Minimum documentation standards
- Example request/response pairs
- Authentication/authorization documentation
Common Pitfalls
1. Hiring "Any Backend Engineer"
The mistake: You assume any competent backend engineer can build good APIs. You hire based on general backend skills without assessing API-specific thinking.
What happens: The engineer builds APIs that work but are confusing to consume—inconsistent naming, unhelpful errors, no versioning strategy. Internal teams complain, and external developers struggle.
Better approach: Specifically assess API design sensibility. Ask candidates to design an API for a hypothetical use case, then probe their decisions. Look for candidates who ask questions about consumers before diving into implementation.
2. Documentation as an Afterthought
The mistake: You prioritize shipping endpoints and plan to "document later." Documentation never becomes a priority.
What happens: Developers consuming your API spend excessive time figuring it out. Support burden increases. Adoption suffers. Integration partners get frustrated.
Better approach: Hire engineers who view documentation as part of the feature, not a separate task. Include documentation in your "definition of done." Consider dedicated technical writing support for larger API initiatives.
3. Ignoring Versioning Until It's Too Late
The mistake: You ship your first API version without a versioning strategy. When you need to make breaking changes, you have no clean path forward.
What happens: You're stuck with bad design decisions or forced to break existing consumers. Migration becomes painful and contentious.
Better approach: Hire engineers who think about versioning from day one. Your first API should be /v1/ with a clear strategy for how v2 would work. Even if you never need v2, the planning ensures better initial design.
4. Over-Designing for Imaginary Consumers
The mistake: You try to build the "perfect" API that handles every possible use case, including ones that don't exist yet.
What happens: Over-engineered endpoints that are complex to maintain. Delays in shipping. Analysis paralysis on design decisions.
Better approach: Design for known consumers first. Build extensibility where it's cheap (like accepting additional fields) but don't pre-build features for hypothetical use cases. Good API design accommodates evolution without requiring it upfront.
5. Treating Internal APIs Differently Than External
The mistake: You apply rigorous design standards to public APIs but let internal APIs be ad-hoc. "It's just for our team."
What happens: Internal APIs become a mess of inconsistency. New team members struggle to integrate. Technical debt accumulates rapidly. Eventually, internal APIs need to become external—and require complete rewrites.
Better approach: Apply similar standards to internal and external APIs. Internal can be less formal on documentation, but design consistency matters everywhere. Your internal API today might be your partner API tomorrow.
6. Hiring for Framework Over Fundamentals
The mistake: You hire based on specific framework experience (Express, FastAPI, NestJS) rather than API design fundamentals.
What happens: You get engineers who can implement endpoints but can't design good contracts. They know how to use the framework but not when to deviate from its defaults.
Better approach: Prioritize understanding of HTTP, REST principles, and API design patterns over specific framework experience. Strong engineers learn frameworks quickly; design sensibility takes longer to develop.
Building Your API Culture
The best API teams share certain cultural traits:
Consumer Obsession
- Every API decision starts with "how will this be consumed?"
- Engineers regularly talk to API consumers
- Dogfooding—using your own APIs—is mandatory
Documentation Pride
- Great documentation is celebrated, not just tolerated
- Engineers compete to write the clearest examples
- Docs are reviewed as carefully as code
Stability Respect
- Breaking changes are treated seriously
- Deprecation periods are honored
- Backward compatibility is valued
Design Consistency
- Patterns are documented and followed
- Deviations require justification
- New endpoints feel familiar
Building this culture requires hiring engineers who value these traits and creating processes that reinforce them.