Mar 2023 – Aug 2023

Multi-Language REST API SDK Engineering

Telnyx · API Engineer

Languages Supported

Full

Unit + Integration Tests

REST

API SDK

Validated Changes

Growth & Stability

~60%

API Response Time Reduced

30+

Manual Workflows Eliminated

1000s

Real-time Synced Users

Overview

At Telnyx, I built and maintained the company's REST API SDK across six programming languages — adding and fixing API coverage and writing unit and integration tests for every change, so developers get reliable, idiomatic clients in their language of choice.

The Problem

Developers needed idiomatic SDKs in multiple languages, not raw REST calls

SDK coverage had to stay in sync with the evolving REST API

Behavior had to stay consistent across all six language SDKs

Every change needed test coverage to avoid breaking client integrations

Maintaining parity across languages is error-prone without discipline

The Solution

REST API SDKs implemented across six programming languages

New API endpoints added and existing ones fixed across the SDKs

Unit and integration tests written for all SDK changes

Consistent patterns applied across language implementations

Continuous integration validating changes

Architecture

Core Components

Per-language SDK packages (6 languages)API endpoint coverage (additions and fixes)Unit and integration test suitesContinuous integration validation

Technical Design

REST API client libraries across six languages

A shared API surface mapped consistently per language

Unit and integration test harnesses per SDK

CI pipeline validating SDK changes

My Role: API Engineer

Developed the Telnyx REST API SDK in six different languages

Added new API endpoints and fixed existing ones across SDKs

Wrote unit and integration tests for all SDK changes

Kept SDK behavior consistent across languages

Key Achievements

🔥

Delivered a REST API SDK across six programming languages

🔥

Established unit and integration test coverage for SDK changes

🔥

Kept multi-language SDKs in sync with the REST API

Impact

📊

Gave developers reliable, idiomatic clients in their language of choice

📊

Reduced integration friction for Telnyx API consumers

📊

Improved SDK reliability through consistent test coverage

Tech Stack

SDKs

REST API client libraries in 6 languages

Testing

Unit and integration tests

Delivery

Continuous integration

Domain

Telecom / communications APIs

What I Help With

Scalable Backend Systems

High-performance APIs and microservices

Complex Integrations

Stripe, Shopify, Microsoft Graph, telecom

AI & Automation

LLM workflows, document processing

Identity & Security

OAuth, Entra ID, Cognito

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