Senior Software Engineer

Whispp is hiring a Senior Development Engineer to help bring our real‑time Whisper‑to‑Speech SDK to smartphones and mobile devices worldwide.

About Whispp

Whispp is an award-winning deep-tech startup headquartered in Leiden, building our real-time on-device Voice Reconstruction AI that converts whispered, affected, and noisy speech into a person's clear, natural voice — all in under 100 ms, on-device, with full speaker identity preservation. The technology is commercialized through SDK licensing to smartphone OEMs, PC OEMs, chipset vendors, and hearing-protection manufacturers. Whispp has active proof-of-concept programs with tier 1 OEMs, and is on a trajectory toward its first integrations.

The opportunity

Our goal is to ship Whispp on mobile devices globally, starting with Android. As a Senior Development Engineer, you will:

• Build and evolve the

Whisper‑to‑Speech (W2S) & Privacy SDK

that OEMs and app developers integrate.

• Help deliver low‑latency, on‑device voice AI on mobile CPUs/NPUs with strong UX and reliability.
• Work closely with AI/speech researchers, product, and OEM partners to validate, optimise, and ship Whispp on real devices.

What you’ll do

• Implement and maintain Whispp’s SDKs, including public APIs, sample apps, and integration tooling for OEMs and app developers.
• Integrate and optimize on‑device AI models (CPU/NPU) to achieve target end‑to‑end latency and robustness for whispered/affected/noisy speech.
• Build demo and reference apps that showcase key use cases: accessibility, silent & discreet calls, noise‑heavy environments, and low‑bitrate connectivity.
• Collaborate with the AI/ML team to define model interfaces, streaming behavior, buffering, and audio I/O on mobile.
• Work with engineering teams at SoC partner and smartphone OEM companies during PoCs: debug integration issues, profile performance, and adapt to different device constraints.
• Contribute to integration documentation, best practices, and internal tooling for automated tests, performance benchmarks, and device lab runs.
• Help monitor real‑world performance and reliability metrics and feed improvements back into the SDK and platform.

What we’re looking for

Must-have

• 6+ years of professional experience in software development using C++ and Kotlin/Java, with a focus on building customer-facing SDKs or high-performance real-time mobile applications.
• Strong experience with audio or real‑time features on mobile (e.g., AudioReach, AudioRecord/AudioTrack, low‑latency audio pipelines, media APIs).
• Experience working on software optimization on CPU and/or GPU.
• Experience integrating native libraries or ML models on mobile (e.g., TensorFlow Lite, ONNX Runtime, or custom runtimes) or a strong willingness to learn.
• Hands-on experience with applying cryptographic algorithms on mobile devices.
• Solid understanding of performance, threading, memory, and battery considerations on constrained mobile devices.
• Good communication skills and comfort collaborating with cross‑functional teams and external partners.
• Willingness to travel to customer locations roughly 30% of the time to support our forward-deployment model.

Nice-to-have

• Experience working with chipset‑specific optimisations (CPU/NPU, DSPs) on Android devices.
• Experience working with Android JNI/NDK.
• Previous SDK/platform work for OEMs or large B2B customers.
• Experience with security enclaves and TEEs on x86 and ARM platforms.
• Familiarity with audio/DSP, voice/speech processing, WebRTC, or similar real‑time communication stacks.
• Exposure to consumer products or lifestyle technologies, or products used in noisy/mission‑critical environments.

Who you are

• You enjoy working close to the metal, making real‑time features feel smooth and invisible to users.
• You