AI Frameworks Engineer

Modular; United States; On-site; USD 198,000 - 319,000; Full time

Benefits offered by this job

Premier insurance plans

401k matching

Flexible paid time off

Stock options

Job summary

Modular is seeking an AI Library Architect for MAX to own core APIs and developer experience for inference and training of AI models. You will work at the intersection of API design, systems engineering, and modern AI frameworks, shaping a coherent programming model across Python and Mojo-adjacent surfaces and driving RFCs and specs.

Based in the US or Canada, you can work in our Los Altos, CA office or remotely from home. Onboarding for new hires is conducted in-person in Los Altos, CA.

Qualifications

• Significant experience designing developer-facing APIs (SDKs, frameworks, or platforms).
• Fluency in systems languages (C++, Rust, Go) and Python; Mojo familiarity a plus.
• Experience with inference and training systems, including model execution graphs, compilation, runtime scheduling, distributed execution, checkpointing.

Responsibilities

• Influence the design of the API surface for MAX: namespaces, core abstractions, extension points, programming model, compatibility guarantees and developer experience.
• Design inference APIs for real-world serving needs: model loading, distributed inference, quantization, tokenization/pipelines, configuration surfaces, batching/streaming, deployment ergonomics.
• Design training APIs that scale from single device to distributed execution with device placement, parallelism, checkpointing, and observability.
• Create a coherent programming model across Python and Mojo-adjacent surfaces: align naming, types, and conventions; avoid leaky abstractions; define the 'pit of success'.
• Drive RFCs and technical specs: write and socialize proposals; gather feedback; iterate towards consensus.
• Partner cross-functionally with compiler/runtime, kernels, cloud/serving, and documentation/DevRel teams to map APIs to underlying capabilities.
• Build reference implementations and exemplar code: golden-path examples, architecture templates, best-practice patterns.
• Set quality bars for APIs: versioning policy, deprecation strategy, test strategy, and documentation requirements.

Skills

APIs design

C++

Rust

Go

Python

PyTorch

JAX

TensorFlow

Mojo

System design

Job description

At Modular, we’re on a mission to revolutionize AI infrastructure by systematically rebuilding the AI software stack from the ground up. Our team, made up of industry leaders and experts, is building cutting-edge, modular infrastructure that simplifies AI development and deployment. By rethinking the complexities of AI systems, we’re empowering everyone to unlock AI’s full potential and tackle some of the world’s most pressing challenges.

If you’re passionate about shaping the future of AI and creating tools that make a real difference in people’s lives, we want you on our team. You can read about our culture and careers to understand how we work and what we value.

About the role:

At Modular, we are building a next generation AI platform to power modern applications and facilitate access to cutting-edge hardware. The MAX Framework is our developer-facing layer: it defines the APIs developers use to express models, integrate custom kernels, orchestrate execution, iterate on quality and ship systems into production.

As an AI Library Architect for MAX, you will own and evolve core APIs and developer experience for inference and training of AI models. You will work at the intersection of API design, systems engineering, and modern AI frameworks. Your output will be the specifications, abstractions, and reference implementations that make MAX feel coherent, powerful, and intuitive to use — while preserving performance, portability, maintainability and TCO.

LOCATION: Candidates based in the US or Canada / United States / San Francisco Bay Area / Seattle are welcome to apply. You can work in our office in Los Altos, CA or remotely from home. Onboarding for new hires is conducted in-person in our Los Altos, CA office.

What you will do:

• Influence the design of the API surface for MAX: namespaces, core abstractions, extension points, programming model, compatibility guarantees and developer experience.
• Design inference APIs that support real-world serving needs: model loading, distributed inference, quantization, tokenization/pipelines, configuration surfaces, batching/streaming, and deployment-oriented ergonomics.
• Design training APIs that scale from single device to distributed execution, with clear primitives for device placement, parallelism, checkpointing, and observability.
• Create a coherent programming model across Python and Mojo-adjacent surfaces: align naming, types, and conventions; avoid leaky abstractions; define the "pit of success".
• Drive RFCs and technical specs: write and socialize proposals; gather feedback from internal model engineers and external users; iterate towards consensus.
• Partner cross-functionally with compiler/runtime, kernels, cloud/serving, and documentation/DevRel teams to ensure APIs map cleanly to underlying capabilities.
• Build reference implementations and exemplar code: golden-path examples, architecture templates, and best-practice patterns that teams can copy.
• Set quality bars for APIs: versioning policy, deprecation strategy, test strategy, and documentation requirements.

What you bring to the table:

• Significant experience designing and evolving developer-facing APIs (SDKs, frameworks, or platforms).
• Strong understanding of modern AI frameworks and their design tradeoffs (e.g., PyTorch, JAX, TensorFlow, vLLM, XLA/MLIR-adjacent ecosystems).
• Experience with inference and training systems (model execution graphs, compilation, runtime scheduling, distributed execution, checkpointing, performance tuning).
• Fluency in one or more systems / performance languages (C++, Rust, Go) and one or more user-facing languages (Python; familiarity with Mojo is a plus).
• Excellent taste for API ergonomics: naming, composability, types, error handling, configurability, and clarity.
• Strong written communication: you can write specs that engineers can implement without ambiguity.
• High engineering standards, pragmatism, and a bias towards incremental development without compromising long term design.

What Modular brings to the table:

• Amazing Team. We are a progressive and agile team with some of the industry’s best engineering and product leaders.
• World-class Benefits. In order to attract the best, we need to offer the best. Premier insurance plans, up to 5% 401k matching, flexible paid time off, and more are available to you! Please note that specific benefit packages may vary based on your location.
• Competitive Compensation. We offer very strong compensation packages, including stock options. We want people to be focused on their best work and believe in tailoring compensation plans to meet the needs of our workforce.
• Team Building Events. We organize regular team onsites and local meetups in Los Altos, CA as well as different cities. Traveling 2-4 times a year is expected for all roles.

Working at Modular will enable you to grow quickly as you work alongside incredibly motivated and talented people who have high standards, possess a growth mindset, and a purpose to truly change the world.

The estimated base salary range for this role to be performed in the US, regardless of the state, is $198,000 - $319,000 USD.

The estimated base salary range for this role to be performed in Canada, regardless of the province, is $194,000.00 - $313,000.00 CAD.

The estimated base salary range for this role to be performed in the United Kingdom is £115,000.00 - £185,000.00 GBP.

For candidates who fall outside of the listed requirements, we nevertheless encourage you to apply as we may have openings that are lower/higher level than the ones advertised.

Modular is proud to emphasize an equal opportunity, safe environment for people to do their best work. Modular is an affirmative action employer. We are committed to providing equal employment opportunities regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, or Veteran status. We also consider qualified applicants regardless of criminal histories, consistent with legal requirements.

If you require reasonable accommodations to participate in the interview process, please let your recruiter know, and we will work with you to meet your needs in compliance with the ADA.

This employer participates in E-Verify and will provide the federal government with your Form I-9 information to confirm that you are authorized to work in the U.S. If E-Verify cannot confirm that you are authorized to work, this employer is required to give you written instructions and an opportunity to contact Department of Homeland Security (DHS) or Social Security Administration (SSA) so you can begin to resolve the issue before the employer can take any action against you, including terminating your employment. Employers can only use E-Verify once you have accepted a job offer and completed the Form I-9.

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