Software Engineer, C - Codebase Q&A

Weekday AI; United States; Remote; USD 148,000 - 210,000; Full time

Job summary

Weekday AI is seeking an experienced C engineer to join a remote, task-based engagement building datasets to train AI agents on real codebases. You will select tasks from validated C repositories, investigate runtime behavior across complex subsystems, and craft questions and rubrics that challenge frontier reasoning.

You'll work asynchronously with US, India, and Nigeria time zones, review by multiple engineers, and document your findings in task READMEs.

Qualifications

• 3+ years of professional software engineering experience with substantial production C
• Ability to navigate a large unfamiliar C codebase and reason about runtime behavior
• Familiarity with preprocessor-heavy builds, platform conditionals, manual memory management, and autotools/CMake/Meson
• Experience with databases, cryptography, networking protocols, or systems programming
• Ability to use debuggers, sanitizers, tracing, and profilers to verify code behavior
• Precise written English for crafting questions, rubrics, and documentation

Responsibilities

• Select tasks from a pre-validated pool of C repositories, each pinned to a specific git commit and arriving with an engineering question, positive and negative rubrics, foils, and a golden solution
• Explore the repository until you genuinely understand the subsystem in question, including the relevant PR or issue history
• Rewrite the task's question so it defeats frontier coding agents while remaining well-defined and fairly answerable
• Adjust rubrics and foils so they reward correct reasoning and reject plausible-but-wrong answers
• Run the full validation loop in Studio — Check, Golden, Run, Analyze — and iterate until every stage passes
• Document your work in the task README and submit for expert review, addressing reviewer feedback on returned tasks

Skills

C language

Codebase navigation

Runtime reasoning

Security awareness

Tools

GDB

Valgrind

Sanitizers

Profilers

Tracing

Job description

This role is for one of our clients

Compensation: $130 per task

We are seeking experiencedC engineersto build the dataset that teaches AI agents to reason about real codebases.

Codebase Q&A is a reinforcement-learning environment for training AI agents to explore and reason about software repositories they have never seen before. You will build difficult codebase-exploration tasks: high-level engineering questions about foundational C systems that cannot be answered by reading a single file, and that require runtime evidence to resolve — the kind of question a senior engineer answers by actually investigating the system.

This track works on some of the most consequential C codebases in production anywhere:PostgreSQL, Redis, git, OpenSSH, OpenSSL, curl, libuv, libgit2, libarchive, Open vSwitch, tcpdump, tmux and zstd.

Contract, task-based work paid at$130 per approved task, performed remotely in our Studio.

Key Responsibilities

• Select tasks from a pre-validated pool of C repositories, each pinned to a specific git commit and arriving with an engineering question, positive and negative rubrics, foils, and a golden solution
• Explore the repository until you genuinely understand the subsystem in question, including the relevant PR or issue history
• Rewrite the task's question so it defeats frontier coding agents while remaining well-defined and fairly answerable
• Adjust rubrics and foils so they reward correct reasoning and reject plausible-but-wrong answers
• Run the full validation loop in Studio — Check, Golden, Run, Analyze — and iterate until every stage passes
• Document your work in the task README and submit for expert review, addressing reviewer feedback on returned tasks

Ideal Qualifications

• 3+ years of professional software engineering experience, with substantial production C
• Demonstrated ability to navigate a large, unfamiliar C codebase and explain how it behaves at runtime — not just what the source says
• Comfort with the things that make C systems hard to read: preprocessor-heavy builds, platform conditionals, manual memory management, and autotools/CMake/Meson build graphs
• Experience with databases, cryptography, networking protocols, or systems programming is highly relevant — the task mix is weighted toward architecture and system design (39%) and code onboarding (34%), with a meaningful security slice
• Ability to use debuggers, sanitizers, tracing, and profilers to establish what the code actually does
• Precise written English: the questions and rubrics you write are the product

Working Details

• Fully remote and asynchronous, with expert team leads across US, India, and Nigeria time zones
• Work is performed in our Studio; time is tracked with Insightful, and platform access is provisioned through Okta
• Onboarding requires identity verification, a background check, signed Terms of Work and CIIAA, a tax form, and passing a short calibration quiz before task access is granted
• Payment is per approved task; every task is reviewed by a second engineer and a super reviewer before acceptance

We consider all qualified applicants without regard to legally protected characteristics and provide reasonable accommodations upon request.