Staff Fullstack Engineer - Internal Tools

lilt-corporate; United States; On-site; USD 120,000 - 180,000; Full time

Job summary

LILT is seeking a senior software engineer in the United States to own end-to-end production systems on our AI-powered translation platform. You will develop across Python backend, React frontend, and data pipelines, influencing long-term architecture and tooling for hundreds of external contributors.

Join a fast-growing team delivering scalable workflows, robust QC, and seamless API integrations with leading AI services.

Qualifications

• 5+ years of professional full-stack software engineering experience, with a track record of owning production systems end-to-end across more than one runtime/language.
• Deep experience with a Python backend framework (FastAPI or comparable) plus async SQLAlchemy/Postgres, alongside production experience in at least one statically-typed backend language (Go, Java, or similar).
• Strong React/TypeScript frontend experience - component architecture, state management (Zustand, Redux, or similar), and a modern data-fetching layer (TanStack Query or comparable).
• Experience building and operating background job/worker systems (queue-driven or polling-based) with failure tolerance and idempotency in mind.
• Experience integrating with third-party and platform APIs - including the GitHub API, OAuth/OIDC SSO, and at least one LLM API (Gemini, OpenAI, or similar) - handling auth, rate limits, and webhook-driven sync.
• Experience building Slack (or comp

Responsibilities

• Translate new benchmark and data-quality requirements into scoped technical designs.
• Own the internal workforce-management tools on our internal platform for AI delivery for hundreds of external contributors: vetting flows, candidate assessment, QC, payment/delivery tracking, and roster/reporting exports.
• Own architecture and long-term technical direction across multiple services and the platform.
• Extend IAA and audio-QA pipelines: annotator outlier detection, ASR sidecar enhancements, LLM-based QC, and DNSMOS/librosa audio-quality scoring.
• Design and ship new modules on the platform that plug new benchmark and vetting workflows into the existing multi-stage review lifecycle.
• Own and extend the platform's API key provisioning and budget-governance system.
• Build self-serve ChatOps-style automation for the internal engineering org and contributor base to enable accelerated annotator workflows and query resolution.
• Harden background worker and job-processing infrastructure.
• Set and enforce testing, CI/CD, and deployment practices across both codebases - from unit/integration testing through infrastructure-as-code and release automation.
• Raise the technical bar for a small, high-leverage team through code review, design docs, and mentoring as the surface area grows.

Skills

Full-stack engineering

Python (FastAPI)

Async SQLAlchemy

React/TypeScript

Background jobs

API integration

Tools

GitHub API

OAuth/OIDC

LLM APIs

Job description

About LILT

AI is changing how the world communicates - and LILT is leading that transformation. We’re on a mission to make the world’s information accessible to everyone , regardless of the language they speak. We use cutting-edge AI, machine translation, and human-in-the-loop expertise to translate content faster, more accurately, and more cost-effective without compromising on brand, voice, or quality. At LILT, we empower our teammates with leading tools, global collaboration, and growth opportunities to do their best work. Our company virtues- Work together, win together; Find a way or make one; Dance in the customer's shoes; Quicker than they expect; Quality is Job 1 -guide everything we do. We are trusted by Intel Corporation , Canva , the United States Department of Defense , the United States Air Force , ASICS , and hundreds of global Enterprises. Backed by Sequoia, Intel Capital, and Redpoint, we’re building a category-defining company in a $50B+ global translation market being redefined by AI.

What You’ll Do

• Partner with the benchmarking business's researchers and TPMs to translate new benchmark and data-quality requirements into scoped technical designs
• Own the internal workforce-management tools on our internal platform for AI delivery for hundreds of external contributors: vetting flows, candidate assessment, QC, payment/delivery tracking, and roster/reporting exports
• Own architecture and long-term technical direction across multiple services and the platform
• Extend IAA and audio-QA pipelines: annotator outlier detection, ASR sidecar enhancements, LLM-based QC, and DNSMOS/librosa audio-quality scoring
• Design and ship new modules on the platform that plug new benchmark and vetting workflows into the existing multi-stage review lifecycle
• Own and extend the platform's API key provisioning and budget-governance system
• Build self-serve ChatOps-style automation for the internal engineering org and contributor base to enable accelerated annotator workflows and query resolution
• Harden background worker and job-processing infrastructure
• Set and enforce testing, CI/CD, and deployment practices across both codebases - from unit/integration testing through infrastructure-as-code and release automation
• Raise the technical bar for a small, high-leverage team through code review, design docs, and mentoring as the surface area grows

What We’re Looking For

Required

• 5+ years of professional full-stack software engineering experience, with a track record of owning production systems end-to-end across more than one runtime/language
• Deep experience with a Python backend framework (FastAPI or comparable) plus async SQLAlchemy/Postgres, alongside production experience in at least one statically-typed backend language (Go, Java, or similar)
• Strong React/TypeScript frontend experience - component architecture, state management (Zustand, Redux, or similar), and a modern data-fetching layer (TanStack Query or comparable)
• Experience building and operating background job/worker systems (queue-driven or polling-based) with failure tolerance and idempotency in mind
• Experience integrating with third-party and platform APIs - including the GitHub API, OAuth/OIDC SSO, and at least one LLM API (Gemini, OpenAI, or similar) - handling auth, rate limits, and webhook-driven sync
• Experience building Slack (or comp