Principal Software Engineer

Location: Bengaluru | Experience: 9 to 12+ years | Compensation: 50 to 60 LPA

About ResultFlow.ai

At ResultFlow.ai , we build AI that helps ecommerce stores convert more of their visitors into customers. Merchants add our JavaScript plugin to their site, and our AI runs experiments and personalises their pages automatically, carrying learnings from one store to the next. It is a genuinely hard problem that spans frontend, backend, data, and LLM systems, all running on real, live stores where correctness matters.

We are a small, fast-moving team that makes decisions with data and ships quickly. We are now looking for a Principal Engineer to be the technical anchor of the company.

This is a hands-on role.

We want to be completely clear, because “Principal” means different things at different places.

This is an individual-contributor role, and you will be in the code every day. This is not an advisory, architecture-only, or oversight position. You will not be managing people or reviewing from a distance while others build. You will be designing systems and building them, solving the hardest problems yourself, and shipping real work alongside the team.

Your influence will come from the quality of what you build and the standard you set, not from a layer of management between you and the product. If your idea of a Principal role is one where you have stopped writing code, this is not the role for you. If you are a deeply experienced engineer who still loves to build and wants your hands on the hardest problems, please keep reading.

What you will do

• Design and build the most important and most difficult parts of our product, end to end.
• Own major technical decisions: the stack, the patterns, and the trade-offs, and defend them with clear reasoning.
• Work across the full stack: frontend that runs on third-party sites, backend APIs and integrations, data at scale, and LLM-powered systems.
• Take fuzzy business problems and turn them into clear technical plans, then execute them.
• Care about scale, reliability, performance, and the real cost of running systems in production.
• Raise the bar for everyone around you through how you build, review, and think.

What we are looking for

• 9 to 12+ years of professional software engineering experience.
• A track record of having designed and owned significant systems end to end , not just built features inside someone else’s design.
• Deep, hands-on strength across most of the stack:
• Frontend: real understanding of how the browser works (rendering, the DOM, the event loop, networking, performance).
• Backend: strong command of a language such as Python or Java, and deep experience with API design, authentication, and third-party integrations.
• Deployment: comfortable owning how systems are deployed and operated, on a VPS or via orchestration such as ECS or Kubernetes.
• Data: real experience with data warehouses and data at scale.
• ML and LLMs: solid grasp of core ML concepts and hands-on experience building with LLM APIs in production, including their parameters and failure modes.
• Judgment and ownership: you make sound technical calls, own the outcomes, and make the team better.
• The mindset we value across the whole team: data-driven, questioning, strong opinions held loosely, a fast and deep learner, a sense of urgency, and clear communication.

A strong plus

• Direct experience with experimentation systems, A/B testing or bandit methods, personalisation, or data instrumentation pipelines. This is the core of what we do.

How our process works

Our hiring is work-first. If you progress, you will complete a practical task and then discuss it with us in depth, including your design and architectural decisions, so we can see how you actually think and build. Using AI tools is welcome throughout, as long as you understand and can explain everything you produce.

If you are a builder at heart with the experience to match, we would love to hear from you.