API design & systems integration
For teams whose tools don't talk to each other: I design clean, well-documented APIs and build the integrations between them, so your data moves without copy-paste and your systems stop being islands.
What's included
Wire the systems together, keep the contracts honest. Every integration engagement ships with:
- An audit of the systems and data flows you have today
- API design with written documentation, OpenAPI where it earns its keep
- Integration builds: CRMs, payment and email providers, and your own internal systems
- Webhooks and event handling, including the retry and failure paths
- Authentication done properly: API keys, OAuth, least-privilege scopes
- Tests that fail loudly when a contract breaks
- Versioning and monitoring guidance, with ongoing monitoring available separately
Careful plumbing, done in the open
Integrations fail when nobody mapped the edge cases. Mapping them is the job.
Discovery
I map every system that touches the data: what holds the truth, what copies it, what breaks when the copy is wrong. The output is a written plan and a fixed quote.
Build
Contract first: the interface is defined and agreed before either side is wired to it. Every endpoint and handler ships with tests that treat the contract as law.
Launch
Cutover is planned, not heroic: run in parallel where it matters, verify the data landed, and keep a rollback path open until both sides agree the numbers match.
Support
Monitoring can be purchased separately. Vendor API updates, other changes, and maintenance are available at an agreed hourly rate. I discuss proposed work with you before starting.
Questions I hear a lot
What buyers usually want to know before opening up their systems.
Can you integrate the specific tools we use?
If a tool offers an API and documentation, very likely — the familiar names in CRM, payments, email, and accounting all do. If it doesn't, I will tell you what the realistic options are, from file-based exchanges to vendor support, and which ones I would not recommend. The audit in discovery exists precisely to answer this before you commit.
How do you price integration work?
New projects are fixed-price, based on the mapping from discovery: the number of systems, the shape of the data, and the failure handling you need. The written scope and quote are agreed before development starts. Changes and maintenance can be provided at an agreed hourly rate. Monitoring is available if purchased separately.
REST, GraphQL, something else?
The boring right answer: plain HTTP with JSON for most integrations, because it is debuggable with tools every developer already has. Heavier machinery earns its complexity only when a genuine need is on the table. Whatever we choose, it is documented well enough that the next developer can work with it.
Who owns the integration code?
You do — completely. When a project is paid for, the source code, configuration, and documentation I produced are yours, with no license fees and no lock-in. If you ever want the work continued by another developer, everything needed to pick it up is in the handover.
What happens when a vendor changes their API?
Vendors can change or retire APIs, so integrations need ongoing attention. Monitoring is available if purchased separately; it is not included automatically with the initial build. Changes and maintenance can be provided at an agreed hourly rate. I discuss the work with you before starting, but cannot guarantee advance notice of every vendor change or prevent every interruption.
We don't have an API of our own — can you design one?
Yes — that is the design half of the work. I design the API the way consumers wish every API worked: predictable resources, clear errors, versioning from day one, and documentation that stays true. Whether it is consumed by your own mobile app or by outside developers, the contract is written down before the code is.
Systems that model a real business
StringBench, the platform I built for racquet stringing professionals, tracks inventory down to half-reel precision and generates QR-coded job labels — the kind of exactness that only matters if the data underneath is trustworthy.
Integrations usually live inside a bigger product. I also build custom web apps and cross-platform mobile apps.
Tired of copy-paste between systems?
Tell me which tools refuse to talk to each other. I'll map the shortest honest path between them.
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