Founding Staff / Principal Engineer

Own product delivery across our SaaS platform, cloud infrastructure integrations, and developer tools, from customer problem to production.

Remote first · Flexible hours · Berlin time zone overlap preferred

You must be able to travel to Berlin for work. We do not offer visa sponsorship.

The role

Proofline reviews code changes against the infrastructure they will deploy into. The product connects code, Terraform and cloud configuration, and deployment evidence so engineers can investigate failures before a change reaches production.

This is a founding role working directly with our founder, Mohsen Azimi. You will start as a hands-on principal individual contributor, writing and reviewing code, owning core SaaS architecture, and shipping product workflows end to end, with a clear path to grow and manage the engineering team as we scale.

You will move fluidly between systems design, product decisions, and implementation. That could mean building out a multi-tenant SaaS workflow, tracing a failed cloud connection, resolving how a Terraform change interacts with live AWS permissions, improving a review's explanation, or debugging a database bottleneck. You use AI coding agents heavily to multiply your output, and you stay responsible for the quality and reliability of the result in production.

Read about how we work and what we offer.

What you will own

  • Build out the core SaaS application. Own complete customer workflows from connecting a GitHub repository and cloud environment, to running asynchronous reviews, inspecting evidence in the web console, and managing organization and access boundaries.
  • Develop deep Terraform and cloud infrastructure integrations. Build integrations that reflect how production cloud environments actually operate across AWS and Google Cloud. Handle Terraform state and plans, IAM permissions, networking, resource discovery, changing cloud state, and partial API responses, and make configuration failures immediately understandable to the user.
  • Turn customer problems into focused releases. Talk directly to the engineers using Proofline, reproduce the friction they encounter, choose a pragmatic scope, and carry the change through design, implementation, verification, and rollout.
  • Improve the developer tools and API experience. Build capabilities that fit naturally into the CLI, SDKs, editors, and GitHub workflows, with clear contracts, useful errors, and considered compatibility.
  • Improve review quality through reproducible evaluation. Investigate unsupported findings, missed failure scenarios, and incomplete reviews. Use concrete production cases to guide changes in our AI review pipelines and verify their effect.
  • Own reliability, performance, and operating cost. Investigate slow reviews and failed jobs, understand database and cloud provider bottlenecks, and make measured improvements without weakening evidence or tenant isolation.
  • Set the engineering standard as we grow. Write maintainable code, document architectural decisions, choose tests that catch consequential failures, and help hire and lead engineers as the team expands.

The problems you will work through

A review combines systems that change at different times: a Git revision, Terraform and infrastructure-as-code definitions, live cloud observations, asynchronous jobs, and external provider APIs. The conclusion must stay strictly tied to the evidence the review actually used.

You will reason about retries, idempotency, data consistency, and strict security boundaries between customer organizations. You will also translate that underlying complexity into a clean SaaS product experience, so an engineer can diagnose a failed setup or assess a deployment risk in seconds.

What you bring

  • 10+ years of professional software development experience, with substantial responsibility for architecting, shipping, and operating production SaaS applications. You remain happiest doing hands-on implementation work and debugging hard failures yourself, with the desire to grow into engineering leadership over time.
  • Strong track record of end-to-end SaaS build-out. You can design and ship multi-tenant backend services, PostgreSQL schemas, asynchronous job pipelines, external integrations, and clean React/TypeScript web interfaces.
  • Deep hands-on experience with Terraform and cloud infrastructure. You understand AWS and/or Google Cloud (IAM permissions, networking, containers, databases, Terraform/IaC state, and CI/CD pipelines) from building and operating real systems.
  • High-velocity, AI-native workflow. You know how to orchestrate coding agents in parallel to research, implement, and test changes rapidly across the stack, while exercising strict engineering judgment over the architecture and final code.
  • Product judgment grounded in developer experience. You can choose what to build, explain what to leave out, and spot when an API, CLI command, or UI screen makes a routine task harder than it needs to be.
  • Clear communication about tradeoffs and evidence. You can take an ambiguous customer problem, turn it into a bounded technical change, and prove that it works.

Useful bonus experience

Experience with static or dynamic code analysis, AI-assisted developer tools, evaluation harnesses, or cloud infrastructure graph models is a strong plus.

The systems you will work on

Our stack includes Rust for the review service, Go for the infrastructure model, PostgreSQL, and React with TypeScript for the web console. Our developer tools include a CLI, Python and TypeScript SDKs, and editor integrations. Cloud and delivery integrations center on Terraform, AWS, Google Cloud, and GitHub.

Prior experience with Rust is not required. We care far more about your depth in SaaS application architecture, Terraform, and cloud infrastructure. With strong systems fundamentals and modern AI coding tools, we expect you will become productive in Rust and across our codebase very quickly.

What success looks like

  • Self-serve SaaS onboarding and workflows: Customers can complete the path from connecting their code and cloud infrastructure to acting on a useful review with minimal manual intervention.
  • Complete, operable releases: Product changes address observed customer needs and ship as reliable end-to-end workflows across backend, integrations, and UI.
  • Measured quality and reliability: Review quality, latency, and infrastructure changes are backed by reproducible evaluations and clear operational telemetry.
  • A codebase ready for scale: Tenant isolation, security boundaries, historical evidence, and recovery paths hold firm as capabilities and team size grow.

Logistics & Compensation

  • Location: Remote globally, with overlap in the Berlin time zone preferred and full access to our Berlin office.
  • Travel: You must be able to travel to Berlin regularly for working sessions, in addition to our quarterly team offsites. Because we do not offer visa sponsorship, you must hold work authorization in your country of residence and have visa-free (or self-sponsored) travel access to the Schengen Area.
  • Compensation: Competitive base salary localized to your location, paired with meaningful founding-team equity. Specific salary and equity ranges for your location are shared prior to the first interview.

How to apply

Instead of a traditional resume screen, inbound consideration starts with a meaningful pull request that adds a new feature to one of Proofline's open source repositories. Documentation-only changes do not meet this requirement.

With modern AI coding agents, this should take roughly 30 to 60 minutes. We use this step to filter out low-effort spam and see how quickly you can understand our developer tools and ship clean, working code.

  1. Choose a repository: the CLI, Python SDK, TypeScript SDK, or Chrome extension. Identify a real user need and implement a useful new feature.
  2. Open a pull request ready for review: Explain who the feature helps, the decisions you made, and how you verified it. The PR does not need to be merged before you contact us.
  3. Email careers@proofline.sh with the PR link, the role you are applying for, and a brief introduction to your relevant experience. (If we reached out to you directly, simply reply to our message.)