Senior API & Integration Engineer

API & Integration

Atlanta, GA, US Hybrid Full-time $125,000 – $180,000

Winixx Inc. is a New York-based technology holding company operating a portfolio of over 35 SaaS platforms across freight, fleet management, financial infrastructure, and market intelligence. We are now building WinixxOS — a distinctive, AOSP-based operating system powering a full lineup of consumer hardware including phones, tablets, smartwatches, POS devices, and gaming consoles. Founded with a mission to modernize fragmented and underserved industries, Winixx builds technology that removes inefficiencies, creates transparency, and puts more value in the hands of the people doing the actual work.

This is early-stage, high-ownership platform engineering — you would be shaping foundational decisions for a new OS, not implementing someone else's spec.

The Senior API & Integration Engineer designs and builds the Winixx SDK — the core API surface plus device-class extensions that third-party developers will build against. You will ensure AOSP compatibility holds up across our custom fork while exposing stable, well-documented APIs across our entire hardware lineup.

• Design and build the core Winixx SDK API surface, plus device-class extensions (POS payment APIs, console input APIs, wearable sensor APIs)
• Ensure standard Android API compatibility is preserved where intended across the custom AOSP fork
• Define versioning and stability guarantees for the SDK, including OS‑update resilience for third‑party apps
• Build and maintain the simulator's API‑level fidelity to real on‑device behavior
• Collaborate with the UI team to expose declarative layout and adaptive UI APIs
• Work with the Security team to ensure new API surfaces are reviewed for security implications
• Author SDK documentation and best‑practice guides for third‑party developers
• Support the developer relations effort by triaging SDK feedback from early access partners

• 5+ years of experience building platform SDKs or APIs, with direct AOSP or Android framework experience
• Deep understanding of Android API design, versioning, and backward‑compatibility practices
• Experience building APIs for diverse hardware/device classes (mobile, embedded, wearable, or POS)
• Familiarity with designing for OS‑update resilience without requiring app rebuilds
• Strong documentation and API design instincts — you think like an SDK consumer
• Comfortable working in an early‑stage environment defining the API surface from scratch
• Bachelor's degree in Computer Science or equivalent experience

• Competitive base salary commensurate with experience
• Performance bonus program tied to individual and company milestones
• Visa sponsorship available for the right talent
• Full‑time role with a minimum one‑year commitment
• Front‑row seat at a company building a new OS and hardware ecosystem from the ground up
• Collaborative, mission‑driven team environment
• Paid time off and company holidays
• Professional development and continuing education support

Winixx Inc. is an equal opportunity employer. We evaluate all applicants on the basis of qualifications, experience, and demonstrated ability without regard to race, color, religion, sex, national origin, disability, veteran status, or any other characteristic protected by applicable law.

This is a full‑time position with a minimum one‑year commitment. Visa sponsorship is available for candidates with the right qualifications and experience.

The compensation range reflected in this posting represents the minimum and maximum target range for this position. Individual pay within the posted range is determined by a candidate's demonstrated experience, educational background, skill set, and geographic location. Final compensation is established at the time of offer and may fall anywhere within the stated range based on these factors.

Compensation ranges reflect national US market data and are subject to change. Additional forms of compensation may include performance bonuses, equity participation, and other benefits as outlined in your offer documentation.