Staff Fullstack Engineer - Internal Tools is a full-time role based in the USA that suits an experienced software engineer looking to build and run internal platforms for Applied AI benchmarking businesses. Lilt is hiring this position to support its internal tooling group, focusing on systems used by delivery, contributor-ops, and engineering teams.
Role Overview
Staff Fullstack Engineer - Internal Tools is a role based in the USA at Lilt. The person in this position will build and operate internal platforms that support Applied AI benchmarking operations. Responsibilities include owning end-to-end architecture, designing data pipelines, and maintaining production-ready tooling that sits on the critical path of customer deliverables.
Key Responsibilities
Partner with researchers and technical program managers to translate benchmark and data-quality requirements into technical designs.
Own internal workforce-management tools for hundreds of external contributors, including vetting flows, quality control, payment tracking, and roster exports.
Direct the long-term architecture and technical strategy across multiple services and platforms.
Extend annotation and audio-quality pipelines, including annotator outlier detection, automatic speech recognition sidecar enhancements, and scoring tools.
Design and ship new modules for benchmark and vetting workflows within the review lifecycle.
Manage API key provisioning and budget-governance systems.
Build self-serve ChatOps-style automation for internal engineering and contributor bases.
Harden background worker and job-processing infrastructure.
Establish and enforce testing, CI/CD, and deployment practices across codebases.
Raise the technical bar through code reviews, design documentation, and mentorship.
Requirements
Five or more years of professional full-stack software engineering experience with end-to-end production systems across multiple runtimes.
Experience with a Python backend framework like FastAPI, async SQLAlchemy, Postgres, and at least one statically-typed backend language such as Go or Java.
React and TypeScript frontend experience, including component architecture, state management, and modern data-fetching layers.
Experience building and operating background job or worker systems with failure tolerance and idempotency.
Experience integrating third-party and platform APIs such as GitHub, OAuth/OIDC SSO, and LLM APIs.
Experience building Slack bot integrations that automate internal workflows with operational guardrails.
Familiarity with applied-statistics or machine-learning-adjacent code such as agreement metrics and audio-quality scoring.
Grasp of CI/CD, containerized deployment, and infrastructure-as-code.
Experience debugging and optimizing native-library memory growth in long-running Python worker processes.
Experience building internal platforms that increase leverage for non-engineering teams.
Nice to Have
Experience with audio or speech pipelines like Whisper, DNSMOS, or librosa.
Experience building internal tools for managing data-labeling or crowdsourced-contributor workforces.
Experience with inter-annotator agreement or statistical agreement metrics.
Notification and delivery systems experience including transactional email and Slack integrations.
Experience designing abstractions over heterogeneous data sources.
Experience building ChatOps-style automation for Slack or GitHub.
Experience implementing short-lived service-to-service JWT authentication alongside human-facing SSO.
Experience operating as a primary engineer on a small internal platform.
Familiarity with LLM-as-judge or LLM-based quality assurance pipelines.
Familiarity with OpenTelemetry instrumentation in Go services.
Familiarity with LLM provider gateway and routing services.
Experience with data export and reporting tools.
Skills and Tools
Python
FastAPI
SQLAlchemy
Postgres
Go
Java
React
TypeScript
Zustand
Redux
TanStack Query
GitHub API
OAuth/OIDC SSO
LLM APIs
Slack API
Docker
Helm
ArgoCD
Terraform
OpenTelemetry
Salary and Benefits
Salary range of $190K to $230K
Equity offers included
About the Company
Lilt is an AI transformation company on a mission to make global information accessible across languages. The organization combines artificial intelligence, machine translation, and human-in-the-loop expertise to translate content for global enterprises and organizations such as Intel, Canva, the United States Department of Defense, the United States Air Force, and ASICS. Backed by Sequoia, Intel Capital, and Redpoint, Lilt operates in the translation market.
How to Apply
Apply on the official company careers page.
