Senior / Staff Software Engineer (Python, JavaScript and iOS SDK)

🌍 Location: North & South America (preferred), Poland, Ukraine & Eastern Europe
💼 Employment: Full-time | B2B
📅 Duration: 3+ months, potential extension
💰 Rate: Up to $25/hour
🚀 Seniority: Senior / Staff

About the Project
We are looking for an experienced Senior / Staff Software Engineer to join a product engineering team building a SaaS platform focused on marketing attribution, conversion tracking, and real-time data processing.

The primary focus of this role is to design and build a mobile attribution SDK from scratch, alongside developing real-time conversion APIs, tracking integrations, and scalable data pipelines.
This is a hands-on engineering position for someone who enjoys building production-grade products, designing reusable abstractions, and solving complex integration challenges.

What You'll Do
Mobile Attribution SDK (Greenfield Project)
Design and develop a new mobile attribution SDK from scratch.
Build and maintain JavaScript and iOS SDK components.
Develop reliable tracking, attribution, and event collection mechanisms.
Design reusable SDK architecture with performance, scalability, and maintainability in mind.
Ensure seamless integration with client applications and backend services.
Conversion API & Real-Time Tracking
Build and maintain real-time conversion tracking integrations using Python.
Process tracking signals and forward conversion events to advertising platforms.
Develop integrations with third-party advertising APIs, handling platform-specific requirements.
Work with Google Pub/Sub and Shopify JavaScript tracking.
Ensure data accuracy, reliability, and efficient event processing.
Data Pipelines & Product Engineering
Design and optimize production data pipelines supporting SaaS product functionality.
Build backend services and product integrations.
Contribute to full-stack application features when needed.
Participate in architectural decisions and technical design discussions.

Requirements
5+ years of commercial software engineering experience, preferably at Senior or Staff level.
Strong production experience with Python.
Hands-on experience developing JavaScript SDKs.
Experience building or maintaining native iOS SDKs (Swift / Objective-C).
Strong SQL skills and experience working with production databases.
Solid understanding of SDK architecture, API design, event tracking, and asynchronous processing.
Experience building customer-facing software products, not only internal tools or dashboards.
Ability to design scalable engineering abstractions and make architectural decisions.
Experience integrating third-party APIs.
Strong problem-solving skills and ability to work independently.
Fluent English for technical discussions and collaboration.

Nice to Have
React Native SDK development experience.
Android SDK development (Kotlin / Java).
Experience with mobile attribution, mobile analytics, or marketing technology (MarTech).
Familiarity with attribution platforms, conversion tracking, or advertising APIs.
Google Cloud Platform (GCP).
Google Pub/Sub, BigQuery, and Apache Airflow.
Shopify tracking integrations.
Experience with streaming architectures and event-driven systems.
Previous experience building developer tools or SDKs from scratch.

Working Conditions
Fully remote, full-time engagement.
Initial project duration of 3+ months, with potential extension.
Hourly rate up to $25 USD.
Preference for candidates based in North or South America.
Candidates from Eastern Europe, especially Poland and Ukraine, are also welcome, provided they can maintain working-hour overlap until approximately 22:00–23:00 local time.

Why Join?
Build from scratch: Own the architecture and implementation of a new mobile attribution SDK.
Real product impact: Work on customer-facing SaaS functionality used in production.
Technical ownership: Influence architecture, SDK design, and integration strategies.
Modern engineering challenges: Work with real-time data, advertising APIs, event streaming, and cross-platform SDKs.
Remote collaboration: Join a distributed engineering team with meaningful technical autonomy.
Interested? Apply with your CV and briefly describe your experience developing JavaScript and/or iOS SDKs, especially any SDKs built from scratch.