API development and integrations
Tankar designs and builds APIs, and connects systems that were never meant to talk to each other. That covers a documented public or partner API for your own product, and the integration layer between your platform and the payment gateway, ERP, CRM, courier or government portal it depends on. Every integration is built with the failure cases handled, because the other side will be slow, will change and will occasionally be down.
The contract comes before the code
An API is a promise to another team. Endpoints, payloads, errors, authentication and rate limits are agreed and written in OpenAPI before implementation, so the client and the server can be built at the same time against the same document.
Built for the day the other side fails
Integrations spend most of their life waiting on someone else's system. Retries, idempotency keys, queues, dead-letter handling and a logged record of every exchange are part of the build, not something added after the first incident.
What stays manual
Some exchanges cannot be automated, usually because the other side has no interface for them. The estimate names those cases so nobody discovers them after launch.
Typical engagements
What this service usually produces, as deliverables rather than adjectives.
- A documented REST or GraphQL API for a partner or mobile client, with versioning and authentication
- Payment gateway integration with webhooks, reconciliation and refund handling
- ERP or CRM integration that keeps customers, orders and invoices in step in both directions
- Logistics integration for rates, labels, pickup and tracking callbacks
- Government or regulator portal integration, including file-based exchanges and signed submissions
- An internal integration layer that replaces point-to-point scripts with one supported interface
How it runs
The stages this service goes through, and what you see at each one.
Discovery
The systems involved, the data that has to move, the direction it moves in, and the rules for what wins when both sides change. Written estimate within 48 hours of the scoped call.
The written estimate follows within 48 hours of the scoped call.
Design
The contract first. Endpoints, payloads, errors, idempotency, authentication and rate limits agreed and written down before implementation starts.
Build
Implementation against the contract, with a sandbox or recorded responses so work does not stop when the other system is unavailable.
Test
Contract tests, retry and timeout behaviour, duplicate handling, and a run against the provider's sandbox with real credentials.
Launch
Rollout with logging of every exchange, alerting on failure rates, and a documented manual path for the cases the integration cannot resolve.
Run
Monitoring of the other side's availability and response times, and a plan for handling their version changes.
- Team shape
- A pod of a project manager, a backend engineer who owns the contract, a second engineer for the client side and a QA engineer.
Stack for this service
The technologies this work is usually built on, and why each one is used here.
| Technology | Why we use it here |
|---|---|
| Node.js | Handles many concurrent outbound calls well, which is what an integration layer mostly does. |
| TypeScript | The contract is expressed as types shared between the API and its clients, so a breaking change shows up at compile time. |
| OpenAPI | One machine-readable contract produces the documentation, the client types and the contract tests, so they cannot drift apart. |
| PostgreSQL | Stores the exchange log and the idempotency keys that make retries safe. |
| Message queues | Slow or unavailable providers are absorbed by a queue with retries and a dead-letter path instead of failing a user's request. |
Selected work
Case studies where this service carried the engagement. Only outcomes with a source are shown.
Own productTravel and hospitalityTripBNG: a B2B travel booking platform for agents
A booking platform that gives travel agents supplier inventory, quotes, credit limits and settlement reports in one account.Services: SaaS product development, API development and integrations and 1 moreRead the case study
Anonymised clientRetail and e-commerceA multi-vendor marketplace with vendor self-service and compliant invoicing
A marketplace where vendors onboard themselves, list and price their own stock, and are paid out against a commission engine with GST-compliant invoices.Services: E-commerce and marketplace development, Custom software development and 1 moreRead the case study
Engagement models that fit
A single named integration is usually fixed price; an integration layer across several systems runs on time and materials.
- Fixed priceA defined scope with a clear end state: an MVP, a website, a well-specified module or an integration.
- Time and materialsEvolving products, research-heavy work such as AI features, and engagements where the backlog is set sprint by sprint.
- Retainer and supportLive products that need maintenance, monitoring, small improvements and a response commitment after launch.
Questions buyers ask
What buyers ask most about this service, answered before the first call.
Tell us what you are building.
NDA on request. Written estimate within 48 hours of a scoped call. Reply within one business day.