Senior SRE

Company: Pylon
Location: San Francisco
Posted on: February 21, 2026

Job Description:

Job Description Job Description At Pylon, we're a small team building a very ambitious product in the mortgage space. At this early stage, we're looking for engineers who can see the opportunity of what we're building towards and want to have a hand in building it. We're in search of people who find difficult problems invigorating and who fit well into a high-performing team built on mutual respect and reliance. If you like pushing yourself to learn a massive amount while shipping code that has a huge impact on the end product, Pylon Engineering could be a great place for you. About the Job You'll own reliability and operational excellence for Pylon's production systems. This means designing and implementing monitoring, alerting, and incident response processes that scale as we grow. You'll build tooling that makes the entire engineering team more effective, establish on-call rotations and runbooks, and ensure our platform can handle the demands of a regulated, high-stakes financial product. This is not a pure ops role. At Pylon, we believe SRE work should be a maximum of 50% operational toil. If you're spending more than half your time firefighting and keeping things running, you're not doing SRE work, you're doing sysadmin work. The other 50% of your time should be spent writing code: building infrastructure tooling, automating away operational burden, making reliability improvements to core services, and creating internal developer productivity tools that make the entire team more effective. SRE is about making things better, not just keeping them alive. We're looking for someone who has operated production systems at scale in a professional engineering environment. You know what good looks like because you've built it before. What We're Looking For Must-haves: 4 years experience in SRE, infrastructure, or platform engineering roles Experience working on a team of SREs at a company with mature SRE practices (not solo SRE roles) Real on-call experience at scale in a large production environment (you've carried the pager and lived through incidents) Deep AWS expertise (ECS, RDS, networking, security) Strong experience with declarative infrastructure (Terraform, CDK, or similar) Nix experience (we use it and want to expand its adoption) Track record of building reliability tooling and automation Can design and implement monitoring, alerting, and observability systems from first principles Comfortable working in a regulated environment where "breaking things" is not an option Nice-to-haves: Experience at companies with strong SRE cultures (Google, Replit, Stripe, etc.) Background in fintech, healthtech, or other regulated domains Experience migrating monitoring systems or implementing SLOs Contributions to infrastructure tooling or open source projects Basics Job title: Senior Site Reliability Engineer Stock options: own a piece of the company and we all win together Health insurance, 401K, dental, etc. Our technology stack: We don't require that you've worked with any of these technologies before, this is just our stack for your information: Infrastructure: AWS (ECS, RDS, CloudFront, Lambda), CDK for infrastructure-as-code Observability: Honeycomb, OpenTelemetry CI/CD: GitHub Actions, Nix for builds and dev environments Core platform: TypeScript/Node backend, PostgreSQL, React frontend Languages: TypeScript, Python, Nix, SQL About you You: Have operated production systems at scale. You've been on-call for a large, complex system. You know what 3am pages feel like and you've built systems to prevent them. You understand the difference between alerts that matter and noise. Write code, not just YAML. You can build internal tools, automation, and reliability improvements. You're comfortable contributing to the core product when reliability requires it. You can read and understand the codebase you're responsible for keeping up. Think in systems. You understand distributed systems, failure modes, cascading failures, and graceful degradation. You can diagnose production issues quickly and know when to escalate vs. when to fix. Know your tools deeply. You've used observability platforms at scale and understand how to instrument systems properly. You can design alerting that has high signal and low noise. You know AWS inside and out. Have strong opinions that you're willing to defend. We have a culture of vigorous discussion and debate on technical decisions. We'll push you to defend your choices, and we want you to push back. Don't settle. Challenge yourself to frequently and consistently deliver exceptional work. If something could be more reliable, take the initiative to improve it. Have great ideas, and lots of them. You should see opportunities all around you to make the infrastructure, tooling and processes better. We'll give you an environment where you can act on those ideas. Are self-motivated. You can take a goal and drive towards it without needing extensive hand-holding. The team is supportive and loves to share knowledge and advice, but there's no time for micromanaging your work. Are comfortable with ambiguity. There's a million ways to do things; you should feel at ease making a decision under uncertainty while balancing competing constraints. Are confident you can learn quickly. Mortgage is complex, our platform is complex, good SRE work is complex. You've got to have an attitude that you can absorb it, get on top of it, and build something better than what came before. Care about developer experience. Your work enables the entire team to ship faster and more confidently. You think about how to make the whole organization more effective. About the TeamWhat we're not: Building a CRUD app: We're building a platform that's only possible due to deep technology investments and thinking hard from first principles. Cargo-culting what's come before won't be sufficient. If you're looking to do mostly plumbing / lego piece assembling, Pylon may be very frustrating for you A ChatGPT wrapper: Mortgage is a sprawling mess of problems, and there isn't one tool that solves every one of them. We use LLMs, but we've reached for tools in multiple disciplines like mixed-integer linear optimization and programming language research. An easy job: We're building a lot of things from the ground up for the first time. Working at Pylon is like a research project where you have to ship to intelligent, opinionated customers regularly. You'll be on-call and responsible for systems that handle real money and real people's mortgage applications. It's basically guaranteed you'll be handed a task that is too difficult for you to do. You might fail sometimes. You might have no idea where to start. Our team leans heavily on each other, but there's no getting around the difficulties. What we are: A small team: We don't have an army of engineers. If you find something is broken, you are probably the best one to fix it All the code we write has to punch above its weight in maintainability and toil reduction If you have a good idea, you have much more ability to put it into action than at a large company We need generalists: specialization is for big companies that already have everything figured out. If you're smart, flexible and like getting into everything, we want you. Working in a regulated space: Mortgage is regulated both federally and at the state level. We move fast, but breaking things isn't an option. About Pylon The $13 trillion mortgage industry at the core of the American economy runs on broken assembly lines with human-powered workflows, stitched-together software, and a series of capital markets intermediates. The costs to originate are at an all time high despite foundational shifts in foundational technology. Pylon is rewiring mortgages from the ground up. We are building the only API-first, programmatic infrastructure that fully automates credit, compliance, capital, and operations. For the first time, originators can build and scale mortgage businesses entirely through software, not people. Our team comes from Stripe, Better, and Affirm, and we are backed by Conversion Capital, QED, Citi, Fifth Wall, Peter Thiel, and the founders of Ramp, Mercury, Blend, and others.

Keywords: Pylon, Daly City , Senior SRE, IT / Software / Systems , San Francisco, California