01Owns
Partner connectors
Builds and maintains the code that talks to each third-party API, including authentication refresh, pagination, field mapping and version upgrades announced by the vendor.
Hire · Integrations
Hire API Integration Developers
Senior API integration developers who join your engineers and connect your product to payment providers, CRMs, logistics partners and internal systems without losing or duplicating records. Shortlisted developers have repaired a flaky webhook consumer, handled a partner’s pagination quirks and documented the failure modes they found.
Paid exercise against a misbehaving mock partner
Senior and lead integrators only
Works in your repositories and monitoring
On your team
What an API integration developer owns on your team.
02Owns
Webhook handling
Verifies signatures, acknowledges quickly, queues the payload for processing and makes each handler safe to run twice when the sender redelivers.
03Owns
Retry and back-off policy
Decides which failures deserve a retry, how long to wait, when to give up and where abandoned messages go so someone can replay them later.
04Owns
Data reconciliation
Runs scheduled comparisons between your records and the partner’s, reports drift and fixes the root cause rather than overwriting one side by hand.
05Owns
Integration documentation
Keeps a short page per partner covering credentials owners, sandbox quirks, rate limits, known outages and who to contact when something breaks.
Vetting
Skills we test before an API integration developer joins.
01Tested
Authentication flows
OAuth 2.0 authorisation code and client credentials grants, token rotation, scoped API keys and signed requests such as HMAC headers.
02Tested
Idempotent design
Uses idempotency keys, natural identifiers and upserts so that a repeated request or replayed event never creates a second order or payment.
03Tested
Contract reading
Reads OpenAPI and AsyncAPI specifications critically, spots undocumented behaviour in sandbox responses and writes contract tests that catch vendor changes.
04Tested
Queues and workers
Moves slow or unreliable partner calls off the request path into queues such as SQS, RabbitMQ or a database-backed job runner.
05Tested
Observability for integrations
Adds correlation IDs, structured logs per partner call and alerts on error rates or lag, so failures surface before customers report them.
06Tested
Data mapping
Translates between mismatched schemas, currencies, time zones and status codes, and records the mapping decisions somewhere the next developer can find them.
Work sample
How the API integration developer work sample runs.
- 01Step 1
Tame a hostile mock API
The developer integrates with a mock partner that rate-limits, times out and occasionally returns duplicate pages, and must sync every record exactly once.
- 02Step 2
Fix a webhook consumer
They receive a handler that processes events in the request thread and double-charges on redelivery, then restructure it with signature checks and idempotency.
- 03Step 3
Plan a version migration
Given notice that a partner is retiring an endpoint, they write a cut-over plan with a dual-running period and a rollback step. We pay for the time spent.
- 04Step 4
Explain a failure to support
They talk a support lead through why a customer’s order never reached the warehouse, using logs, without blaming the partner or the customer.
Levels
API Integration Developers: what changes at each level.
01Level 1
Senior
Owns several partner connectors end to end, chooses retry and queueing patterns for them and reviews integration code from colleagues.
02Level 2
Lead
Sets shared conventions for authentication, logging and error handling across all integrations, and decides which partners get a dedicated connector.
03Level 3
Integration architect
Shapes the overall integration approach: event bus or point-to-point, where an integration platform earns its licence and how data ownership is split between systems.
Other options
When to hire someone other than an API integration developer.
01Consider
Most integrations are inside Salesforce
If the work is mostly flows, Apex callouts and connected apps within the CRM, a Salesforce developer will move faster.
Open register02Consider
You need a whole backend, not connectors
If the product itself is missing its server, database and business logic, start with a backend generalist.
Open register03Consider
ERP is the system of record
When most data flows in and out of SAP and its interfaces, an SAP specialist understands the other end better.
Open registerIntegrations fail at the edges, so test the edges
Calling a well-documented endpoint once is easy. The difficult part of integration work is what happens on the thousandth call: a token expires mid-batch, the partner returns a 200 with an error in the body, or a webhook arrives before the record it refers to exists. Interview questions that only cover the happy path tell you very little.
Ask candidates to describe an integration that broke in production and what they changed afterwards. Experienced integrators answer with specifics about retries, ordering and reconciliation, not just about the vendor being unreliable.
Exactly once is a design choice, not a setting
Most queues and webhook senders guarantee at-least-once delivery, which means duplicates are normal. The integrator’s job is to make the receiving side tolerate them, usually with idempotency keys or a stored record of processed event IDs. A developer who expects the network to deliver each message precisely once will eventually create double orders.
Choosing the right level
A senior integrator is the right hire when you know which partners to connect and need them built and kept healthy. Bring in a lead once integrations have multiplied and each one handles credentials, logging and failure differently. An integration architect is worth it when the number of systems makes the overall pattern, not any single connector, the main risk.
A useful first month
Ask the new hire to inventory every existing integration: what it calls, who owns the credentials, how failures are noticed and when it was last changed. The list usually reveals at least one connector nobody is watching.
Then pick the integration that causes the most support tickets and let them rebuild its error handling first. Fewer manual fixes for the support team is the clearest early sign the hire is working.
FAQ
Questions to resolve before the build.
01Which partners have your API integration developers worked with?
Typical histories include payment providers, shipping and logistics APIs, CRMs, accounting systems and identity providers. On the shortlist we list the specific platforms each candidate has shipped against so you can match them to yours.
02Do they build integrations in our language and framework?
Yes. We match on the stack you already run, most often Node.js, Python, Java, PHP or .NET, so connectors live alongside the rest of your code rather than in a separate tool nobody maintains.
03Can they work with an integration platform instead of custom code?
Several have configured iPaaS tools as well as writing code. A good integrator will tell you honestly which partners suit a platform connector and which need custom handling because of volume or awkward behaviour.
Works alongside
Roles an API integration developer works best alongside.
01Pair with
Node.js developers
When the core product runs on Node and new partner calls must fit the existing service structure and test suite.
Open register02Pair with
DevOps engineers
For queue infrastructure, secret storage for partner credentials and alerting that pages the right person.
Open register03Pair with
QA engineers
To build regression suites against partner sandboxes and catch breaking vendor changes before a release.
Open registerProduct delivery
Need the whole product built instead?
Primary sources
References behind this page
Dated official documentation, standards, and research that support the factual claims on this page.
- 01RFC 6749: The OAuth 2.0 Authorization Framework
The IETF specification behind most partner API authentication flows.
- 02OpenAPI Specification
The published standard for describing HTTP APIs and their contracts.
How to read this page
Scope, cost and timeline figures are planning guidance until confirmed in a written proposal. Diagrams and screens are illustrations, not client deliverables, and source-code rights and handover follow the signed agreement. See the delivery process and the full disclaimer.
Next decision
Turn the brief into an accepted product scope.
Define outcomes, constraints, evidence, rights and handover before delivery begins.
Commercial rights, repositories, environments, documentation, acceptance and handover remain contract-defined.