Applied ML Engineer ($170k-$280k + Equity) at Macroscope

Jack & Jill; San Francisco (CA); On-site; USD 170,000 - 280,000; Full time

Benefits offered by this job

Equity 0.25%-0.5%

Job summary

Macroscope, a San Francisco-based startup, is hiring an Applied ML Engineer to own the ML lifecycle for our agent-powered development infrastructure. You will focus on training and fine-tuning LLMs using advanced reinforcement learning techniques and build evaluation datasets to drive model improvements.

You'll work with backend engineers on production integration using Golang, Temporal, and AST code walkers, contributing to core infrastructure and code-quality tooling.

Qualifications

• 3+ years of applied ML experience in production or research.
• Hands-on RL for LLMs (RLHF, DPO, GRPO) with training dynamics.
• Strong software engineering skills and reliable ML pipelines.

Responsibilities

• Train and fine-tune LLMs using RL methods to improve code generation.
• Design datasets and benchmarks to measure model performance.
• Collaborate with engineers to deploy models into production.

Skills

Applied ML

RL for LLMs

Software pipelines

Golang

Temporal

AST code walkers

Tools

Golang

Temporal

AST code walkers

Job description

Job Title

Applied ML Engineer

Salary

$170k-$280k + Equity

Company Description

Macroscope is a San Francisco-based startup building infrastructure for agent-powered software development, backed by Lightspeed, Thrive Capital, and Google Ventures. Founded by repeat exited entrepreneurs from Periscope and Magic Pony, the team is creating tools that allow engineers to direct fleets of agents with automated code review and verification.

Job Description

As an Applied ML Engineer at Macroscope, you will own the machine learning lifecycle for our agentic software development infrastructure. You will focus on training and fine-tuning LLMs using advanced reinforcement learning techniques like GRPO and DPO. By building high-quality evaluation datasets and rigorous benchmarks, you'll drive model improvements that empower engineers with unprecedented leverage.

Location

San Francisco, USA

Why this role is remarkable

• You will perform deep technical work in reinforcement learning (RLHF, DPO, GRPO) and model training, moving beyond simple API wrappers to build core agentic infrastructure.
• Macroscope is led by veteran founders who previously exited Periscope and Magic Pony, and is supported by top-tier investors including Lightspeed, Thrive Capital, and Google Ventures.
• You'll receive significant early-stage equity (0.25%-0.5%) at a valuation that offers massive upside compared to later-stage competitors, working in a high-agency, flat-structured environment.

What You Will Do

• Train and fine-tune LLMs using reinforcement learning techniques such as GRPO, DPO, and PPO to improve reasoning and code generation capabilities.
• Design and curate high-quality evaluation datasets and benchmarks to rigorously measure model performance and guide product-driven experimentation.
• Collaborate with backend engineers to integrate custom models into production using a stack featuring Golang, Temporal, and custom-built AST code walkers.

The ideal candidate

• Has 3+ years of experience in applied ML, specifically building, fine-tuning, or evaluating modern models in production or research environments.
• Possesses hands‑on experience with reinforcement learning for LLMs (RLHF, RLAIF, or similar) and a deep understanding of training dynamics and reward shaping.
• Demonstrates strong software engineering skills and a high‑agency mindset, comfortable building reliable ML pipelines in a fast‑paced, in‑office San Francisco startup.

We never post fake jobs

This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it.