Required:

• 3+ in Windows desktop application development using Windows App SDK, WinUI (or similar), C#, XAML — and ideally additional experience with native Windows code (C++, Win32/WinRT/COM).
• Deep understanding of Windows application architecture, including interop between managed code (.NET) and native code.
• Proven track record of designing, building, and shipping production-quality desktop applications, with an emphasis on reliability, performance, scalability, and maintainability.
• Strong experience with accessibility APIs on Windows (e.g. Microsoft UI Automation or similar), and a dedication to building accessible and inclusive software.
• Excellent software engineering fundamentals: OOP, design patterns, data structures, algorithms, memory management, multi-threading or asynchronous programming (where relevant).
• Experience leading technical design, mentoring other engineers, conducting code reviews, and making architecture-level decisions.
• Strong communication skills; ability to articulate tradeoffs, collaborate with cross-functional teams, and drive consensus.
• A user-centric mindset: focus on building polished, intuitive, and accessible experiences for end users.

Preferred / Bonus:

• Experience with writing automated tests for UI — unit tests, integration tests, UI automation tests; familiarity with relevant testing frameworks.
• Experience with performance optimization for desktop apps (memory usage, startup time, rendering performance, high-DPI support, responsiveness under load).
• Experience with localization/globalization, right-to-left UI support, internationalization, accessibility for multiple regions.
• Familiarity with telemetry, analytics, crash reporting, logging, and error monitoring in desktop applications.
• Previous experience in shaping CI/CD workflows, release pipelines, and deployment strategies for desktop applications.
• Demonstrated ability to take ownership of feature areas or modules and drive them long-term, including maintenance, refactoring, and technical debt management.

What we offer

• A high-impact role: you will define architecture, shape the future of our Windows product, and directly influence what millions of users see and experience.
• A collaborative, flat-structure engineering culture — you are not just a coder, but a builder and a decision-maker.
• Opportunities to lead — mentor others, steer technical direction, and grow into broader technical leadership (e.g. Tech Lead, Architect).
• Flexibility, autonomy, and responsibility: you define how to solve problems, own features end-to-end, and contribute to long-term product vision.
• A purpose-driven mission: building software that’s reliable, accessible, and user-centered — making a real difference for people.                  

Think you’re a good fit for this job? 

Tell us more about yourself and why you're interested in the role when you apply.
And don’t forget to include links to your portfolio and LinkedIn.

Not looking but know someone who would make a great fit? 
Refer them! 

Speechify is committed to a diverse and inclusive workplace. 
Speechify does not discriminate on the basis of race, national origin, gender, gender identity, sexual orientation, protected veteran status, disability, age, or other legally protected status.

Who we are

Lightricks is an AI-first company creating next-generation content creation technology for businesses, enterprises, and studios with a mission to bridge the gap between imagination and creation. At our core is LTX-2, an open-source generative video model, built to deliver expressive, high-fidelity video at unmatched speed. It powers both our own products and a growing ecosystem of partners through API integration.

The company is also known globally for pioneering consumer creativity through products like Facetune, one of the world’s most recognized creative brands, which helped introduce AI-powered visual expression to hundreds of millions of users worldwide. We combine deep research, user-first design, and end-to-end execution from concept to final render to bring the future of expression to all.

About the Role

As a Large Scale Training Engineer, you will play a key role in enhancing the training throughput of our internal framework and enabling researchers to pioneer new model concepts. This role demands excellent engineering skills for designing, implementing, and optimizing cutting-edge AI models, alongside writing robust machine learning code and understanding supercomputer performance deeply. Your expertise in performance optimization, understanding distributed systems, and bug elimination will be crucial, as our framework supports extensive computations across numerous virtual machines.

This role is designed for individuals who are not only technically proficient but also deeply passionate about pushing the boundaries of AI and machine learning through innovative engineering and collaborative research.

Key Responsibilities

• Profile and optimize the training process to ensure efficiency and effectiveness, including optimizing multimodal data pipelines and data storage methods.
• Develop high-performance TPU/GPU/CPU kernels and integrate advanced techniques into our training framework to maximize hardware efficiency.
• Utilize knowledge of hardware features to make aggressive optimizations and advise on hardware/software co-designs.
• Collaboratively develop model architectures with researchers that facilitate efficient training and inference.
• Design, maintain, and evolve a high-quality, shared codebase that emphasizes correctness, readability, extensibility, testing, and long-term maintainability, while balancing performance requirements.

Your skills and experience

• Industry experience with small to large-scale ML experiments and multi-modal ML pipelines.
• Strong software engineering skills, proficient in Python, and experienced with modern C++.
• Deep understanding of GPU, CPU, TPU, or other AI accelerator architectures.
• Enjoy diving deep into system implementations to improve performance without compromising code quality and maintainability.
• Passion for driving ML large-scale training workloads efficiently and optimizing compute kernels.

* You are encouraged to apply if you meet 3 out of the 5 core qualifications above and are motivated to grow in the remaining areas.

Nice to have

• • Background in JAX/Pallas, Triton, CUDA, OpenCL, or similar technologies.
  • Familiarity with Kubernetes-based environments for running and scaling large-scale workloads.

Why Join Us

We’re here to push the boundaries of what’s possible with AI and video - not for the buzz, but for the craft, the challenge, and the chance to make something genuinely new.
We believe in an environment where people are encouraged to think, create, and explore. Real impact happens when people are empowered to experiment, evolve, and elevate together. At Lightricks, every breakthrough starts with great people and a collaborative mindset. If you're looking for a place that combines deep tech, creative energy, and zero buzzword culture, you might be in the right place.

We got you covered: 

• We run daily door-to-door shuttles, offering Car-to-go subscriptions for several locations in central Israel, plus free parking and train-station pickups.
• We’re proud to have 2 chef-led restaurants on site by the legendary Machneyuda Group (yes, that Machneyuda!), plus a bakery nestled in the heart of our office, filled daily with the scent of fresh pastries.
• We empower employees with cutting-edge tools and learning opportunities to grow and succeed through workshops, access and training on platforms, subscriptions, and clear guidelines for responsible AI use.

Lightricks is an AI-first company creating next-generation content creation technology for businesses, enterprises, and studios with a mission to bridge the gap between imagination and creation. At our core is LTX-2, an open-source generative video model, built to deliver expressive, high-fidelity video at unmatched speed. It powers both our own products and a growing ecosystem of partners through API integration.

The company is also known globally for pioneering consumer creativity through products like Facetune, one of the world’s most recognized creative brands, which helped introduce AI-powered visual expression to hundreds of millions of users worldwide. We combine deep research, user-first design, and end-to-end execution from concept to final render, to bring the future of expression to all.

Why Join Us

We’re here to push the boundaries of what’s possible with AI and video - not for the buzz, but for the craft, the challenge, and the chance to make something genuinely new.

We believe in an environment where people are encouraged to think, create and explore. Real impact happens when people are empowered to experiment, evolve, and elevate together.

At Lightricks, every breakthrough starts with great people and a collaborative mindset. If you're looking for a place that combines deep tech, creative energy, and zero buzzword culture, you might be in the right place.

What you will be doing

 As an ML Software Engineer with a focus on low-level and CUDA-based optimizations, you will play a key role in shaping the design, performance, and scalability of Lightricks’ machine learning inference systems. You’ll work on deeply technical challenges at the intersection of GPU acceleration, systems architecture, and ML deployment.
Your expertise in CUDA, C/C++, and performance tuning will be crucial in enhancing runtime efficiency across heterogeneous computing environments. You’ll collaborate with designers, researchers, and backend engineers to build production-grade ML pipelines that are optimized for latency, throughput, and memory use, contributing directly to the infrastructure powering Lightricks' next-generation AI products.
This role is ideal for an engineer with strong systems-level thinking, deep familiarity with GPU internals, and a passion for pushing the boundaries of performance and efficiency in machine learning infrastructure.

Responsibilities

• Design and implement highly optimized GPU-accelerated ML inference systems using CUDA and low-level parallelism techniques
• Optimize memory, compute, and data flow to meet real-time or high-throughput constraints
• Improve the performance, reliability, and observability of our inference backend across diverse compute targets (CPU/GPU)
• Collaborate with cross-functional teams (including researchers, developers, and designers) to deliver efficient and scalable inference solutions
• Contribute to ComfyUI and internal infrastructure to improve the usability and performance of model execution flows
• Investigate performance bottlenecks at all levels of the stack—from Python to kernel-level execution
• Navigate and enhance a large, complex, production-grade codebase
• Drive innovation in low-level system design to support future ML workloads

Your Skills and Experience

• 5+ years of experience in high-performance software engineering
• Advanced proficiency in CUDA, C/C++, and Python, especially in production environments
• Deep understanding of GPU architecture, memory hierarchies, and optimization techniques
• Proven track record of optimizing compute-intensive systems
• Strong system architecture fundamentals, especially around performance, concurrency, and parallelism
• Ability to independently lead deep technical investigations and deliver clean, maintainable solutions
• Collaborative and team-oriented mindset, with experience working across functional teams

Preferred Requirements

• Experience with low-level profiling and debugging tools (e.g., Nsight, perf, gdb, VTune)
• Familiarity with machine learning frameworks (e.g., PyTorch, TensorRT, ONNX Runtime)
• Contributions to performance-critical open-source or ML infrastructure projects
• Experience with cloud infrastructure and GPU scheduling at scale

Who we are

Lightricks is an AI-first company with a mission to bridge the gap between imagination and creation. At our core is LTX-2, an open-source generative video model, built to deliver expressive, high-fidelity video at unmatched speed. It powers both our own products and a growing ecosystem of partners through api integration.

Our flagship products include Facetune and LTX Studio, used by hundreds of millions of users worldwide. We combine deep research, user-first design, and end-to-end execution to bring the future of expression to all.

What you will be doing

As an ML Software Engineer with a focus on low-level and CUDA-based optimizations, you will play a key role in shaping the design, performance, and scalability of Lightricks’ machine learning inference systems. You’ll work on deeply technical challenges at the intersection of GPU acceleration, systems architecture, and ML deployment.
Your expertise in CUDA, C/C++, and performance tuning will be crucial in enhancing runtime efficiency across heterogeneous computing environments. You’ll collaborate with designers, researchers, and backend engineers to build production-grade ML pipelines that are optimized for latency, throughput, and memory use, contributing directly to the infrastructure powering Lightricks' next-generation AI products.
This role is ideal for an engineer with strong systems-level thinking, deep familiarity with GPU internals, and a passion for pushing the boundaries of performance and efficiency in machine learning infrastructure.

Responsibilities

• Design and implement highly optimized GPU-accelerated ML inference systems using CUDA and low-level parallelism techniques
• Optimize memory, compute, and data flow to meet real-time or high-throughput constraints
• Improve the performance, reliability, and observability of our inference backend across diverse compute targets (CPU/GPU)
• Collaborate with cross-functional teams (including researchers, developers, and designers) to deliver efficient and scalable inference solutions
• Contribute to ComfyUI and internal infrastructure to improve usability and performance of model execution flows
• Investigate performance bottlenecks at all levels of the stack—from Python to kernel-level execution
• Navigate and enhance a large, complex, production-grade codebase
• Drive innovation in low-level system design to support future ML workloads

Your Skills and Experience

• 5+ years of experience in high-performance software engineering
• Advanced proficiency in CUDA, C/C++, and Python, especially in production environments
• Deep understanding of GPU architecture, memory hierarchies, and optimization techniques
• Proven track record of optimizing compute-intensive systems
• Strong system architecture fundamentals, especially around performance, concurrency, and parallelism
• Ability to independently lead deep technical investigations and deliver clean, maintainable solutions
• Collaborative and team-oriented mindset, with experience working across functional teams

Preferred Requirements

• Experience with low-level profiling and debugging tools (e.g., Nsight, perf, gdb, VTune)
• Familiarity with machine learning frameworks (e.g., PyTorch, TensorRT, ONNX Runtime)
• Contributions to performance-critical open-source or ML infrastructure projects
• Experience with cloud infrastructure and GPU scheduling at scale

Why Join Us

We’re here to push the boundaries of what’s possible with AI and video - not for the buzz, but for the craft, the challenge, and the chance to make something genuinely new.
We believe in an environment where people are encouraged to think, create, and explore. Real impact happens when people are empowered to experiment, evolve, and elevate together. At Lightricks, every breakthrough starts with great people and a collaborative mindset. If you're looking for a place that combines deep tech, creative energy, and zero buzzword culture, you might be in the right place.

We got you covered: 

• We run daily door-to-door shuttles, offering Car-to-go subscriptions for several locations in central Israel, plus free parking and train-station pickups.
• We’re proud to have 2 chef-led restaurants on site by the legendary Machneyuda Group (yes, that Machneyuda!), plus a bakery nestled in the heart of our office, filled daily with the scent of fresh pastries.
• We empower employees with cutting-edge tools and learning opportunities to grow and succeed through workshops, access and training on platforms, subscriptions, and clear guidelines for responsible AI use.