Staff Backend Engineer
Summary
Staff backend engineer at Modulate, a Series A voice AI infrastructure company (voice moderation, fraud prevention, AI voice agent oversight) in Cambridge/Boston. You take technical ownership of a fast-growing <100K-line codebase in an agent-first workflow — agents write and review code, you exercise judgment and give final sign-off. Language-agnostic; Python/TypeScript a plus.
Staff Backend Engineer | Modulate
Department: AI/ML/Tech
Location: United States, Cambridge/Boston
Employment Type: FullTime
Role: Staff Backend Engineer
Company: Modulate
Location: Cambridge/Boston, MA, USA. Hybrid, 3 days a week in the office. You need to be US-local. Exceptions are possible for exceptional candidates.
Job Type: Full-time
About Modulate
Modulate is a voice AI infrastructure company at Series A. It started in gaming, with a goal of making online play equitable and less toxic. Its ToxMod system moderates voice chat in Call of Duty, and Rainbow Six Siege cut critical toxic voice chat by 50% with it. Today the company is moving into fraud prevention, customer service and oversight of AI voice agents. Its Velma platform runs an ensemble of 100+ small specialised models, and the Velma model has been open to any developer through an API since June 2026.
Engineering here works in an unusual way. Engineers use agents for all coding, and they work highly independently. The codebase is under 100K lines and growing fast. CI/CD is agentic: one agent writes the code, an adversarial agent reviews the MR, and the two negotiate approval. A human gives the final sign-off.
It seems to work. The latest security audit had zero findings. Ryan, who runs hiring, says it was the first zero-finding audit of his 20-year career, and he credits the agents.
You would join an eng team of about 6 engineers, next to an ML team of about 8.
What you are expected to do:
Take technical ownership in a codebase that is under 100K lines and growing rapidly.
Work independently, with agents doing the coding.
Work inside the agentic CI/CD flow: an agent writes, an adversarial agent reviews the MR, two agents negotiate approval, and a human gives the final sign-off.
What you need to succeed:
You are a senior-level engineer with the judgment to match.
You are comfortable with ambiguity and take technical ownership without waiting to be handed a plan.
You live in the Cambridge/Boston area and can be in the office 3 days a week.
Python and TypeScript are a plus. The role is language-agnostic, so neither is required.
What you get:
Salary: $180,000 to $200,000, plus equity. Other perks: HSA, FSA, 15 holidays and professional growth resources.
High independence and real technical ownership.
An agent-first way of working, where agents write the code in a fast-growing codebase.
A mission with roots in making gaming equitable and non-toxic.
A hiring process that tests judgment. No DSA, no LeetCode, no formal system design questions.
A gift card to cover token spend on the take-home.
How to apply
Apply directly on this page using the application form. We are excited to learn more about you!
The vacancy is proudly presented by the hirehire recruiting agency.
“A rare chance to see what engineering looks like when agents write the code and humans own the judgment, at a voice AI company that already ships to Call of Duty. If you want real ownership and equity upside before Series B, this is it.”
— Leonid Khachaturov, AI/ML Expert, hirehire